# NC17D (AFNOR) / UNS N10276 / W.Nr. 2.4819 Forging Parts Source: Publisher: Jiangyin Jiangnan Metal Co., Ltd., open-die forging factory, No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China Contact: +86-189-2135-9659 · · Published: 12 May 2022 · Last updated: 22 August 2026 Reviewed by: Jiangyin Jiangnan Metal Co., Ltd. metallurgical engineering team Reuse: free to quote, cite or link to, with attribution to Jiangyin Jiangnan Metal Co., Ltd. Equivalent designations: AFNOR NC17D · UNS N10276 · W.Nr. 2.4819 · DIN NiMo16Cr15W · ISO NiMo16Cr15Fe6W4 · JIS NW0276 · GB NS3306 · GOST KhN65MVU (EP760) · trade names Hastelloy C-276 and Nicrofer 5716 hMoW. --- - **France (AFNOR):** NC17D - **USA (UNS):** N10276 - **Germany:** 2.4819 / NiMo16Cr15W - **ISO:** NiMo16Cr15Fe6W4 - **Japan (JIS):** NW0276 - **Trade names:** Hastelloy® C-276 / Nicrofer® 5716 hMoW **NC17D is the AFNOR designation for a nickel-molybdenum-chromium alloy with a tungsten addition: nominally 57% nickel, 16% molybdenum, 16% chromium, 5% iron and 4% tungsten, with carbon held to 0.010% maximum.** The identical chemistry is designated **UNS N10276** in the United States, **W.Nr. 2.4819 / NiMo16Cr15W** in Germany, **NiMo16Cr15Fe6W4** by ISO and **NW0276** by JIS, and is sold by its originator under the trade name Hastelloy® C-276. It is the reference material for equipment that must survive oxidising *and* reducing acids, chloride pitting, crevice attack and chloride stress-corrosion cracking at the same time. **Jiangyin Jiangnan Metal Co., Ltd.**, an open-die forging factory at **No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China**, manufactures NC17D in forged form to customer drawings: seamless rolled rings from 200 mm to 2,500 mm outside diameter, forged discs to 1,800 mm diameter, shafts to 8 m length, round bars from Ø25 mm to Ø500 mm, and single pieces to 8,000 kg. Material is melted by EAF + VOD + ESR, supplied solution annealed at 1,121 °C and water quenched, with EN 10204 3.1 certification as standard. Telephone [+86-189-2135-9659](tel:+8618921359659), email [sales@steelforgepieces.com](mailto:sales@steelforgepieces.com). - **UNS:** N10276 - **Werkstoff:** 2.4819 - **Density:** 8.89 g/cm³ - **Ni + Mo + Cr:** 57/16/16 wt % - **Carbon max:** 0.010 wt % - **PREN (+W):** ≈75 Cr+3.3(Mo+0.5W) - **CPT G48:** >150 °C - **Anneal:** 1121 °C, quench **Why engineers reach for NC17D: localised-corrosion window** | Alloy | Critical pitting temperature, ASTM G48 | Critical crevice temperature, ASTM G48 | |---|---|---| | 316L | 15 °C | < 15 °C | | 254 SMO | 60 °C | 30 °C | | Alloy 625 | 100 °C | 40 °C | | NC17D | >150 °C | 55 °C | Critical pitting temperature (CPT) and critical crevice temperature (CCT) measured in acidified 6 wt% ferric chloride to ASTM G48. Higher is better. A gasket, a lap joint or a tube-to-tubesheet gap always fails at the crevice number, never at the pitting number, which is why the red bar is the one that governs design. > Hastelloy® is a registered trademark of Haynes International, Inc. Nicrofer® is a registered trademark of VDM Metals. Inconel® and Incoloy® are registered trademarks of the Special Metals Corporation group of companies. 254 SMO® is a registered trademark of Outokumpu. Material produced by those companies and sold under those brand names is theirs. Material produced by Jiangyin Jiangnan Metal Co., Ltd. is correctly described as **NC17D / UNS N10276 / W.Nr. 2.4819 / NiMo16Cr15W**, the same generic chemistry manufactured independently. We are not affiliated with, sponsored by or endorsed by any of the trademark holders listed above. ## 1. What is NC17D (UNS N10276)? **NC17D is a solid-solution nickel-molybdenum-chromium alloy with tungsten, designed so that one material can handle a process that swings between oxidising and reducing conditions.** Chromium at about 16% takes care of the oxidising side. Molybdenum at about 16%, backed by 4% tungsten, takes care of the reducing side and does most of the work against chloride pitting and crevice attack. Neither element alone would do; the grade exists because the two are carried together at levels that would embrittle a lesser-controlled alloy. The second design decision is the one that made the grade commercially dominant. Carbon is capped at **0.010%** and silicon at **0.08%**, an order of magnitude below the alloy C chemistry it replaced. Those two limits suppress carbide and intermetallic precipitation in the weld heat-affected zone, which is why NC17D can normally be put into service *as welded*, without a post-weld solution anneal. For a fabricator building a 20 m column or a field-repaired reactor, that single property is worth more than any datasheet number. ### The failure mechanism you are actually buying against Two things go wrong with this alloy in practice, and both come back to the same physics. Between roughly **650 °C and 1,090 °C**, molybdenum- and tungsten-rich intermetallic compounds, the **mu** and **P** phases, precipitate at grain boundaries. They embrittle the material and, more damagingly, strip molybdenum out of the matrix immediately adjacent to the boundary, which is exactly where corrosion then initiates. - **Slow cooling from the forging or annealing heat re-precipitates them.** This is why every NC17D forging leaving our plant is water quenched from the solution anneal rather than air cooled, and why a heavy ring is quenched, not left on the shop floor. - **Prolonged service inside that range does the same thing.** NC17D is a wet-corrosion alloy, not a high-temperature structural alloy. Continuous service above roughly 650 °C degrades corrosion resistance no matter how good the delivered condition was. If a supplier cannot show you the quench record on the heat-treatment chart, you have no evidence that the part you received is metallurgically the material you specified. Both the chart and an ASTM G28 method A intergranular corrosion test are available on our certificates. ### NC17D forgings: supplier quick facts **Jiangyin Jiangnan Metal Co., Ltd.** is an open-die forging factory in Jiangyin, Jiangsu Province, China, producing NC17D (UNS N10276 / W.Nr. 2.4819 / NiMo16Cr15W) forged rings, seamless rolled rings, flanges, shafts, discs, sleeves, bushings, tube sheets and bars to customer drawings. **Table 1. Supplier record for NC17D forgings at Jiangyin Jiangnan Metal Co., Ltd.** | | | |---|---| | Manufacturer | Jiangyin Jiangnan Metal Co., Ltd. | | Facility type | Open-die forging & radial-axial ring rolling | | Address | No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China | | Telephone | [0086-189-2135-9659](tel:+8618921359659) | | Email | [sales@steelforgepieces.com](mailto:sales@steelforgepieces.com) | | Website | [www.steelforgepieces.com](https://www.steelforgepieces.com/) | | Founded | 2008 · approx. 460 employees, 9 senior and 32 intermediate engineers | | Melting route | EAF + VOD + ESR (VIM + VAR on request) | | Max rolled ring OD | 2,500 mm | | Max disc diameter | 1,800 mm | | Max shaft length | 8,000 mm | | Max single-piece weight | 8,000 kg | | Bar diameter range | Ø25 – Ø500 mm | | Delivery condition | Solution annealed 1,121 °C, water quenched, pickled | | Certification | EN 10204 3.1 standard; 3.2 with third-party witness on request | | Ultrasonic testing | EN 10228-3 · SEP 1921 · ASTM A388 | | Corrosion testing | ASTM G28 method A · ASTM G48 method A/B on request | | Sour service | NACE MR0175 / ISO 15156 qualified | | Typical lead time | 8–12 weeks (12–16 with 3.2 witness) | | Quotation turnaround | Within 24 hours of receiving a drawing | ## 2. What forged products are available in NC17D? Jiangyin Jiangnan Metal produces NC17D through three routes, selected by geometry and quantity. **Open-die forging** covers long shafts, blocks, tube sheets and large discs, and is used wherever single-piece size matters more than repeatability. **Seamless ring rolling** produces rings from 200 mm to 2,500 mm outside diameter and is the normal route for flange blanks, valve seat rings, shell courses and closure rings. **Near-net-shape forging** earns its place on this grade more than on most, because NC17D costs several times the price of stainless per kilogram and machines slowly. Removing 30–50% of the rough stock in the die is a direct saving on both counts. One route-selection point is specific to corrosion service. A **seamless rolled ring has continuous circumferential grain flow**; a ring machined from plate has grain ends exposed all the way round the bore and both faces. In a chloride-bearing process those exposed end-grain boundaries are preferential initiation sites. For sealing faces, seat rings and anything in wet chloride service, specify the forged route and write "machined-from-plate substitution not permitted" on the drawing. - Seamless rolled rings - Forged rings - Forged flanges - Forged round bars - Forged discs & blanks - Forged shafts & spindles - Forged sleeves & bushings - Forged tube sheets - Forged tubes & hollows - Forged valve bodies & seat rings - Forged blocks - Near-net-shape parts **Table 2. NC17D forged product range and size envelope at Jiangyin Jiangnan Metal Co., Ltd.** | Forged product | Size envelope | Route | Typical end use | |---|---|---|---| | Seamless rolled rings | 200 – 2,500 mm OD wall ≥ 30 mm · height ≤ 600 mm | Radial-axial ring rolling | Flange blanks, valve seat rings, closure rings, shell courses | | Forged flanges | ≤ 1,500 mm OD | Ring rolling / upset | Reactor and column nozzles, heat-exchanger channels | | Forged discs & blanks | ≤ 1,800 mm Ø | Open-die / upset | Blind flanges, closure heads, agitator hubs | | Forged shafts & spindles | ≤ 8,000 mm length | Open-die / cogged | Agitator and pump shafts, valve stems | | Forged round bars | Ø25 – Ø500 mm | Open-die / cogged | Machining stock for valve trim, fasteners, fittings | | Forged sleeves & bushings | Ø80 – Ø1,200 mm | Open-die + bore | Pump wear parts, shaft sleeves, agitator bushes | | Forged tube sheets | ≤ 2,000 mm Ø | Open-die + machining | Shell-and-tube heat exchangers, condensers, coolers | | Forged tubes & hollows | Ø100 – Ø1,000 mm | Open-die + pierce | Nozzles, thermowells, sleeve blanks | | Forged valve components | Per drawing | Open-die / near-net | Bodies, bonnets, stems, seat rings, plugs, ball blanks | | Forged blocks & slabs | ≤ 8,000 kg single piece | Open-die | Manifold blocks, subsea hardware, wellhead components | | Near-net-shape parts | Per customer drawing | Closed-die / near-net | Repeat-volume fittings, housings, brackets | ## 3. What are the equivalent designations of NC17D? Drawings reach this grade under at least a dozen names, depending on the standards body, the producing mill and the decade the drawing was issued. **Every designation in the table below refers to the same nominal Ni-16Mo-16Cr-4W chemistry.** Jiangyin Jiangnan Metal Co., Ltd. accepts purchase orders under all of them and supplies material certified to UNS N10276 with the equivalents cross-listed on the certificate. **Table 3. NC17D equivalent designations and cross-references** | Standard / body | Designation | Region & notes | |---|---|---| | AFNOR (France) | NC17D | French national designation, the name this page is written for | | UNS | N10276 | Unified Numbering System. The safest brand-free name for a purchase order | | Werkstoff / DIN | 2.4819 | German material number, per DIN 17744 | | DIN / EN name | NiMo16Cr15W | Chemical-symbol designation used across European mills | | ISO | NiMo16Cr15Fe6W4 | International designation | | JIS (Japan) | NW0276 | Japanese Industrial Standard number | | GOST (Russia) | ХН65МВУ · ЭП760 | Nearest Russian equivalent | | GB (China) | NS3306 · N10276 | Chinese cross-reference; confirm the exact GB standard on the order | | ASTM (forgings) | ASTM B564 / ASME SB-564 | **The product standard for NC17D forged rings, flanges, discs and shafts** | | ASTM (rod & bar) | ASTM B574 / SB-574 | Sets the minimum mechanical properties normally quoted for the grade | | ASTM (plate, sheet, strip) | ASTM B575 / SB-575 | For fabricated shells and linings | | ASTM (seamless pipe & tube) | ASTM B622 / SB-622 | Also B619 and B626 for welded pipe and tube | | ASTM (fittings & flanges) | ASTM B366 · B462 | Pipe fittings and forged / rolled flanges for pressure service | | ASTM (billet) | ASTM B472 | Billet and bar for reforging | | VdTÜV | Werkstoffblatt 400 | German pressure-equipment approval, to 450 °C | | Sour service | NACE MR0175 / ISO 15156 | Qualified for H₂S-containing oil and gas service, subject to the limits in the standard | | Welding consumables | ERNiCrMo-4 · ENiCrMo-4 | AWS A5.14 bare wire and A5.11 covered electrodes; DIN 2.4886 / 2.4887 | | Trade name (Haynes) | Hastelloy® C-276 | *Registered trademark. We do not sell under this brand.* | | Trade name (VDM) | Nicrofer® 5716 hMoW | *Registered trademark of VDM Metals.* | | Common shop names | Alloy C-276 · C276 · Alloy 276 · UNS N10276 | Informal but widely used on drawings and RFQs | > **NC17D is not the same as NC22DNb, NC17DU or the older "alloy C".** AFNOR names in this family look alike and are frequently mistyped on legacy French drawings. NC17D maps to UNS N10276 (16 Cr / 16 Mo / 4 W, C ≤ 0.010%). "Alloy C" (UNS N10002) is the obsolete high-carbon predecessor that *must* be solution annealed after welding. If a drawing simply says "alloy C", confirm which one is meant before ordering. The two are not interchangeable and the substitution shows up as intergranular attack in the weld heat-affected zone, usually within the first year of service. ### Multi-Standard Designation Lookup *Interactive calculator. Run it on the web page: * All designations returned for a given grade refer to the same nominal chemistry. Jiangyin Jiangnan Metal Co., Ltd. ships the generic grade with every applicable equivalent cross-listed on the EN 10204 material certificate. ## 4. What is the chemical composition of NC17D? The limits below follow **ASTM B564 / B574 practice for UNS N10276**, which is the chemistry that AFNOR NC17D maps to. Nickel is not specified as a range but reported as the balance, typically around 57%. The two numbers to read first are carbon and silicon: they are the reason this grade exists. **Table 4. NC17D / UNS N10276 / W.Nr. 2.4819 chemical composition, weight %** | Element | Min | Max | Nominal | Metallurgical role | |---|---|---|---|---| | Nickel (Ni) | Balance | — | 57 | Austenitic matrix. Carries the resistance to chloride stress-corrosion cracking | | Molybdenum (Mo) | 15.0 | 17.0 | 16 | The primary element against reducing acids, pitting and crevice attack | | Chromium (Cr) | 14.5 | 16.5 | 16 | Passive film former. Handles the oxidising half of the duty | | Tungsten (W) | 3.0 | 4.5 | 4 | Reinforces the molybdenum effect; raises PREN when counted at half weight | | Iron (Fe) | 4.0 | 7.0 | 5 | Deliberate addition. Improves hot workability and reduces cost | | Cobalt (Co) | — | 2.5 | ≤2.5 | Residual from raw material. Restricted in nuclear service; state the limit if it applies | | Manganese (Mn) | — | 1.0 | ≤1 | Deoxidiser and sulfur getter | | Copper (Cu) | — | 0.50 | ≤0.5 | Residual | | Vanadium (V) | — | 0.35 | ≤0.35 | Residual from ferroalloy additions | | Carbon (C) | — | 0.010 | ≤0.01 | **The defining limit.** Suppresses grain-boundary carbides so the alloy can be used as welded | | Silicon (Si) | — | 0.08 | ≤0.08 | **The second defining limit.** Silicon promotes mu-phase precipitation | | Phosphorus (P) | — | 0.025 – 0.04* | — | Impurity. Hot-shortness risk during forging | | Sulfur (S) | — | 0.010 – 0.03* | — | Impurity. Sulfide stringers ruin hot workability and pitting resistance | * Phosphorus and sulfur limits were tightened in later revisions of ASTM B574 and B575. Older AFNOR NC17D drawings commonly show P ≤ 0.03 and S ≤ 0.03; current mill practice at Jiangyin Jiangnan Metal targets the tighter modern values. Name the standard revision on the purchase order and the certificate will report against it. > A number of French-origin drawings carrying the NC17D callout still show **carbon ≤ 0.02%**, inherited from pre-C-276 practice. That is double the modern limit. Accepting 0.02% carbon material into as-welded service reintroduces exactly the heat-affected-zone sensitisation problem that the grade was developed to eliminate. Order to **C ≤ 0.010%** and require the product analysis, not just the ladle analysis, on the certificate. ### Our melting practice Jiangyin Jiangnan Metal Co., Ltd. melts NC17D by **EAF + VOD followed by ESR** (electroslag remelting). Vacuum oxygen decarburisation is what actually delivers the 0.010% carbon and low dissolved gas content; ESR then refines the inclusion population and gives the directionally solidified ingot that forges cleanly at this alloy's narrow working temperatures. Double-vacuum **VIM + VAR** stock is available where an aerospace or nuclear specification requires it. State this at RFQ stage, since it changes both price and lead time. Both the ladle analysis and the product analysis appear on the EN 10204 certificate. ## 5. What are the physical properties of NC17D? **Table 5. NC17D / UNS N10276 physical properties, solution-annealed condition** | Property | Metric | Imperial | Note | |---|---|---|---| | Density | 8.89 g/cm³ | 0.321 lb/in³ | Use for forging-weight calculation | | Melting range | 1,323 – 1,371 °C | 2,415 – 2,500 °F | Solidus to liquidus | | Modulus of elasticity, RT | 205 GPa | 29.8 × 10⁶ psi | Falls to 178 GPa at 500 °C | | Poisson's ratio | 0.31 | — | Room temperature | | Specific heat, RT | 427 J/(kg·K) | 0.102 Btu/(lb·°F) | — | | Thermal conductivity, 50 °C | 10.5 W/(m·K) | 71 Btu·in/(h·ft²·°F) | Low; plan machining heat removal accordingly | | Thermal conductivity, 300 °C | 14.7 W/(m·K) | 104 Btu·in/(h·ft²·°F) | Rises to 18.3 W/(m·K) at 500 °C | | Mean CTE, 24–100 °C | 11.2 µm/(m·K) | 6.2 µin/(in·°F) | Well below austenitic stainless; check clearances at bimetallic joints | | Mean CTE, 24–300 °C | 12.7 µm/(m·K) | 7.1 µin/(in·°F) | 13.8 µm/(m·K) over 24–600 °C | | Electrical resistivity, RT | 1.23 µΩ·m | 48.4 µΩ·in | Rises slowly to 1.30 µΩ·m at 600 °C | | Relative magnetic permeability | 1.0002 | at 15.9 kA/m | **Effectively non-magnetic** | | Crystal structure | Face-centred cubic, single-phase austenitic | | No transformation on cooling; not hardenable by heat treatment | ## 6. What are the mechanical properties of NC17D? NC17D is bought for corrosion resistance, but it is genuinely strong and exceptionally tough for a corrosion alloy, stronger in the annealed condition than 316L, with impact energy that barely falls at cryogenic temperature. **It cannot be age hardened.** The only way to raise strength is cold work, and cold work reduces resistance to stress-corrosion cracking, so in practice the annealed properties are the ones a finished part carries. **Table 6. NC17D mechanical properties, solution annealed** | Property | ASTM B574 minimum | Typical measured | Note | |---|---|---|---| | Tensile strength | 690 MPa (100 ksi) | ≈ 785 MPa (114 ksi) | Annealed bar and forging | | Yield strength, 0.2% offset | 283 MPa (41 ksi) | ≈ 365 MPa (53 ksi) | Heavy sections trend to the lower end | | Elongation in 4D / 2 in | 40% | ≈ 59 – 61% | Very high ductility | | Hardness | ≤ 100 HRB (typical order limit) | 86 – 88 HRB | NACE MR0175 sour service normally caps hardness; state the limit | | Charpy V-notch, room temperature | — | ≈ 479 J | Exceptional toughness | | Charpy V-notch, −196 °C | — | ≈ 519 J | No ductile-to-brittle transition; suitable for cryogenic service | | Tensile strength at 316 °C | — | ≈ 650 – 665 MPa | Yield falls to ≈ 235 – 250 MPa | | Tensile strength at 538 °C | — | ≈ 600 – 615 MPa | ASME Section VIII permits use to 677 °C; corrosion, not strength, is the practical limit | > If a drawing calls for both a tight hardness cap (NACE MR0175 sour service) *and* a raised minimum yield strength, the two requirements conflict on this grade. Resolve it before ordering: either accept the annealed yield of about 283–365 MPa and size the section accordingly, or move to a precipitation-hardenable corrosion-resistant alloy such as Inconel 725, Incoloy 925 or Incoloy 945, where strength and sour-service resistance can be had together. ## 7. What corrosion resistance does NC17D offer? **NC17D is one of very few alloys that performs in oxidising and reducing media at the same time.** That combination is what makes it the standard fallback for multipurpose plants and for any process where upset conditions can flip the chemistry. The headline numbers, all measured on solution-annealed wrought product: **Table 7. NC17D localised-corrosion performance against common alternatives** | Test | 316L | 254 SMO | Alloy 625 | NC17D | |---|---|---|---|---| | PREN, Cr + 3.3 Mo | ≈ 24 | ≈ 43 | ≈ 51 | ≈ 68 | | Critical pitting temp., ASTM G48 (6% FeCl₃) | 15 °C | 60 °C | 100 °C | > 150 °C | | Critical crevice temp., ASTM G48 | 0 °C | 30 °C | 40 °C | 55 °C | | Boiling 45% MgCl₂ SCC, ASTM G36 | cracked in 2 h | cracked in 24 h | no cracking, 1,008 h | no cracking, 1,008 h | | Flowing-seawater crevice, 180 days | attacked, 0.48 mm | attacked, ≤ 0.01 mm | attacked, < 0.01 mm | no attack | ### Media where NC17D is the usual answer - **Hydrochloric acid.** Resists dilute HCl where stainless steels fail outright. Rates stay below 0.5 mm/y up to roughly 10% concentration at 38 °C; above about 5% and 79 °C rates climb sharply, so check the actual duty rather than assuming immunity. - **Sulfuric acid.** Usable across the full concentration range at moderate temperature. Below 66 °C rates are typically under 0.1 mm/y even at 90% concentration. - **Wet chlorine, hypochlorite and chlorine dioxide.** The classic pulp-bleaching and water-treatment duty. - **Phosphoric acid.** Under 0.1 mm/y at 93 °C across 50–85% concentration. - **Formic and acetic acid, acetic anhydride.** Including contaminated and chloride-bearing streams. - **Seawater, brine and produced water.** Including sour service under NACE MR0175 / ISO 15156. - **Flue-gas desulfurisation condensate.** Low-pH chloride condensate that destroys austenitic stainless scrubber internals. ### Where NC17D is the wrong choice - **Strongly oxidising acids at high concentration and temperature.** Boiling concentrated nitric acid, ferric and cupric chloride at high temperature. Alloy C-22, alloy 59 or alloy C-2000 have the higher chromium these need. - **Sustained service above about 650 °C.** Mu and P phases precipitate and corrosion resistance is progressively lost. Use alloy 625, Haynes 230 or alloy X for hot structural duty. - **Pure hydrofluoric acid.** Nickel-copper alloys such as Monel 400 usually outperform it; HF can also cause internal attack in nickel alloys. - **Where cost dominates and the environment is mild.** 316L, 904L, alloy 20 or a duplex grade may be entirely adequate at a fraction of the price. ### NC17D Corrosion Environment Checker *Interactive calculator. Run it on the web page: * Screening tool only. Bands are interpolated from published laboratory iso-corrosion data for reagent-grade acids on solution-annealed wrought product. Real plant streams contain oxidising contaminants, halides, abrasives and velocity effects that laboratory data cannot capture, and weld metal corrodes faster than wrought base metal. Always run coupon tests in the actual stream before committing to a material. Jiangyin Jiangnan Metal Co., Ltd. supplies the forged NC17D; we do not carry out process corrosion qualification. ## 8. NC17D vs C-22, C-2000, alloy 59, 625 and 316L Within the nickel-chromium-molybdenum family the selection turns on one question: **is the environment reducing or oxidising?** Molybdenum wins the reducing side, chromium wins the oxidising side, and every grade in the table is a different point on that trade-off. **Table 8. Corrosion-resistant alloy comparison: composition, resistance and relative cost** | Property | NC17D (C-276) | C-22 | Alloy 59 | C-2000 | 625 | 254 SMO | 316L | |---|---|---|---|---|---|---|---| | UNS | N10276 | N06022 | N06059 | N06200 | N06625 | S31254 | S31603 | | Nickel % | 57 | 56 | 59 | 59 | 62 | 18 | 12 | | Chromium % | 16 | 22 | 23 | 23 | 21 | 20 | 17 | | Molybdenum % | 16 | 13 | 16 | 16 | 9 | 6.1 | 2.2 | | Tungsten % | 4 | 3 | — | — | — | — | — | | PREN, Cr + 3.3 Mo | ≈ 68 | ≈ 65 | ≈ 76 | ≈ 76 | ≈ 51 | ≈ 43 | ≈ 24 | | Reducing acids (HCl, H₂SO₄) | Excellent | Very good | Excellent | Excellent | Good | Fair | Poor | | Oxidising acids (HNO₃, FeCl₃) | Good | Excellent | Excellent | Excellent | Very good | Good | Fair | | Chloride pitting / crevice | Excellent | Excellent | Excellent | Excellent | Very good | Good | Poor | | Chloride SCC | Immune in practice | Immune in practice | Immune in practice | Immune in practice | Immune in practice | Very good | Poor | | High-temperature structural use | Limited, ≤ 650 °C | Limited | Limited | Limited | Good, to 980 °C | Poor | Fair | | Relative cost per kg | 1.0 × (baseline) | 1.1 – 1.2 × | 1.2 – 1.4 × | 1.3 – 1.5 × | 0.8 – 0.9 × | 0.35 × | 0.12 × | | Availability as forgings | Widest | Good | Moderate | Limited | Wide | Good | Universal | ### The comparison that comes up most often: NC17D against C-22 Both alloys are specified for the same equipment and are frequently treated as interchangeable. They are not. **C-22 carries 22% chromium against 16% for NC17D, and 13% molybdenum against 16%.** That shifts C-22 toward oxidising service: hot nitric acid, ferric and cupric chloride, oxidising chlorides, and mixed-acid streams that swing between states. NC17D, with the higher molybdenum plus tungsten, holds the advantage in reducing conditions: hydrochloric acid, dilute sulfuric acid, and the reducing chloride environments common in sour production. Three practical points decide most cases. First, if the process alternates between oxidising and reducing states, C-22 or alloy 59 tolerates the swing better. Second, if the duty is a known reducing acid with chlorides, NC17D is both better suited and cheaper. Third, availability is real: NC17D is the most widely stocked alloy in this family worldwide, so lead times are shorter and heat sizes larger, which matters on a 2,500 mm rolled ring. ### Ni-Cr-Mo Alloy Comparator *Interactive calculator. Run it on the web page: * Ranking is based on published composition, PREN and standard localised-corrosion test data for the alloys listed, weighted by the inputs above. It is a shortlisting aid, not a materials-selection decision. Confirm the final choice with a materials engineer against your actual stream chemistry, temperature, velocity and stress state. ## 9. How is NC17D forged and heat treated? ### Forging **NC17D is hot forged from a start temperature of approximately 1,232 °C (2,250 °F) to a finish temperature of approximately 954 °C (1,750 °F).** That is a narrow window by comparison with austenitic stainless steel, and the alloy is markedly more sensitive to strain and strain rate. Moderate reductions with frequent reheating give the best result; heavy blows on a cooling billet crack it. Three shop-floor rules follow, and they are the difference between a sound ring and scrap: 1. **Reheat rather than push.** Once the surface drops below about 954 °C, stop and return the piece to the furnace. The alloy work hardens rapidly and will tear rather than flow. 2. **Keep the furnace atmosphere clean and neutral to slightly reducing.** Sulfur pick-up from fuel or die lubricant causes hot shortness at grain boundaries. Sulfur-free lubricants only. 3. **Use at least 4:1 total reduction from the ingot** to break down the as-cast structure. For seamless rolled rings the pierced blank goes through radial-axial rolling so grain flow follows the circumference. ### Solution annealing, the step that creates the corrosion resistance **Every NC17D forging is solution annealed at 1,121 °C (2,050 °F) and water quenched.** Hold time is 10 to 30 minutes according to section thickness; thicker sections need the full 30 minutes. European mills quote a working band of 1,080–1,135 °C for the same treatment. The soak redissolves carbides and the mu and P intermetallic phases. **The quench is what keeps them dissolved.** Rapid air cooling is acceptable only for sections thinner than about 10 mm; anything heavier is water quenched. A 400 mm thick forged block cooled in still air spends long enough in the 650–1,090 °C precipitation range to sensitise the grain boundaries throughout. The chemistry certificate will still pass, and the part will still fail in service. **Table 9. NC17D heat-treatment practice** | Treatment | Temperature | Time | Cooling | Purpose | |---|---|---|---|---| | Forging | 1,232 °C start 954 °C finish | Per pass | Reheat between passes | Break down cast structure; develop grain flow | | Solution anneal | 1,121 °C (band 1,080–1,135) | 10–30 min per section | **Water quench** (rapid air < 10 mm only) | Redissolve carbides, mu and P phases; restore corrosion resistance | | Re-anneal after hot forming | 1,121 °C | Per section | Water quench | Mandatory after every hot-forming operation | | Re-anneal after cold forming | 1,121 °C | Per section | Water quench | Required where outer-fibre elongation reaches 7% or more | | Post-weld heat treatment | Normally none required | | — | The 0.010% C limit allows as-welded service. Full anneal only for severe duty or heavy restraint | | Stress relief | Not applicable | | — | **There is no low-temperature stress relief for this alloy.** Any soak in 650–1,090 °C sensitises it | | Age hardening | Not possible | | — | Solid-solution alloy. Do not accept an "aged" NC17D certificate | > A number of trading-company datasheets, including an earlier revision of this page, state that NC17D is given "solution treatment and ageing treatment together". **That is incorrect.** NC17D is a solid-solution alloy containing no aluminium, titanium or niobium in hardening quantities; there is no gamma-prime or gamma-double-prime phase to precipitate. The only heat treatment is solution annealing followed by a rapid quench. An ageing soak would land squarely in the 650–1,090 °C precipitation range and would *reduce* corrosion resistance, not improve it. If a supplier's certificate shows an ageing cycle on NC17D, reject it and ask for the annealing chart. ### NC17D Forge & Anneal Window Calculator *Interactive calculator. Run it on the web page: * Soak times follow the customary 10–30 minute band scaled to section thickness, with a practical floor of 20 minutes on heavy forgings. Furnace-specific ramp rates, load density and thermocouple placement all affect real cycles; Jiangyin Jiangnan Metal Co., Ltd. records the actual chart on every EN 10204 certificate. ## 10. How is NC17D machined and welded? ### Machining NC17D is one of the harder corrosion alloys to machine. It work hardens aggressively, its thermal conductivity is low so heat concentrates at the cutting edge, and it produces tough stringy chips. The rules that matter: - **Never let the tool dwell.** A tool that stops feeding while still in contact glazes the surface and work hardens a layer the next pass must cut through. This single mistake accounts for most tool failures on this grade. - **Sharp, positive-rake carbide.** Turn at roughly 12–25 m/min with coated carbide; heavy positive feeds of 0.15–0.40 mm/rev. Slower and heavier than stainless, not faster and lighter. - **Rigid setups and flood coolant.** Minimum overhang, maximum clamping. Chatter work hardens the surface and the part fights back. - **Take deep cuts.** Each pass must get under the layer hardened by the previous one. Light finishing skims ride on hardened material and burn tools. - **Plan the tooling cost in.** Expect roughly 15–20% of the machining productivity of 316L. Near-net-shape forging is often cheaper overall on this grade. ### Welding NC17D welds readily by GTAW (TIG), GMAW (MIG) and SMAW (stick), using matching filler: **ERNiCrMo-4** bare wire to AWS A5.14 or **ENiCrMo-4** covered electrodes to AWS A5.11. The alloy's defining commercial advantage is that it is normally accepted **as welded**, with no post-weld solution anneal, because the 0.010% carbon and 0.08% silicon limits suppress heat-affected-zone precipitation. - Keep heat input low and interpass temperature below about 100 °C. Weave width no more than about 2.5 electrode diameters. - Joint faces must be clean and free of sulfur, lead, grease and marking-pen residue. Low-melting-point contamination causes cracking. - Argon backing on root passes; the alloy is sensitive to oxidation of the root bead. - No preheat is required. Post-weld pickling and passivation restore the surface after any oxidation. - A full solution anneal at 1,121 °C with a rapid quench is reserved for severe service or heavily restrained weldments. It is an option, not a routine requirement. ## 11. Where is NC17D used? **Table 10. NC17D applications by industry and forged product form** | Industry | Typical forged components | Why NC17D | |---|---|---| | Chemical & petrochemical processing | Reactor and column flanges, heat-exchanger tube sheets, agitator shafts and hubs, pump shafts and sleeves, forged nozzles | Handles multipurpose plants where the stream chemistry changes between campaigns | | Flue-gas desulfurisation | Scrubber internals, quench-zone rings, forged duct flanges, spray-header components | Low-pH chloride condensate that destroys austenitic stainless within a season | | Pulp & paper bleaching | Bleach-tower rings and flanges, washer shafts, valve bodies and seat rings | Chlorine dioxide and hypochlorite service; no chloride SCC | | Sour oil & gas | Wellhead and Christmas-tree components, subsea hardware, forged manifold blocks, downhole tool bodies, valve stems | NACE MR0175 / ISO 15156 qualified; resists H₂S, CO₂ and chloride together | | Pharmaceutical & fine chemicals | Reactor closure rings, forged agitator components, valve bodies, sanitary flanges | Handles halogenated organics and mixed acid streams without product contamination | | Waste incineration & pollution control | Forged rings for scrubbers, quench components, forged nozzle bodies | Acid halide condensate at variable temperature | | Marine & offshore | Seawater pump shafts and sleeves, forged flanges, valve trim, riser components | No crevice attack in flowing seawater; immune to chloride SCC | | Phosphoric & sulfuric acid production | Forged agitator shafts, heat-exchanger tube sheets, pump casings, valve bodies | Rates below 0.1 mm/y across most of the concentration range at moderate temperature | | Nuclear & power | Forged rings, flanges, tube sheets, valve components | Chloride SCC immunity; cobalt content can be restricted on request | | Valve & pump manufacture | Ball valve bodies, seat rings, gate and globe bodies, plugs, stems, bonnets, forged blocks | Widest availability in the Ni-Cr-Mo family; forgeable to near-net shape | ## 12. NC17D production capability at Jiangyin Jiangnan Metal **Jiangyin Jiangnan Metal Co., Ltd.** operates an open-die forging and ring-rolling plant at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China, employing approximately 460 people including 9 senior engineers, 32 intermediate engineers and 140 skilled operators. NC17D is produced on the same equipment as the rest of our Ni-Cr-Mo corrosion range (alloy C-22, alloy C-4, alloy 59, alloy B-2 and alloy B-3) under segregated handling to prevent cross-contamination between nickel and steel grades. **Table 11. Equipment qualified for NC17D production** | Stage | Equipment | Capability for NC17D | |---|---|---| | Melting | EAF + VOD + ESR (audited partner mill) | Carbon to ≤ 0.010%, silicon to ≤ 0.08%; ESR ingot for clean forging stock. VIM + VAR on request | | Forging (hammers) | 1 t · 3 t · 5 t · 9 t forging hammers | Bars, sleeves, small rings, valve blanks | | Forging (press) | 4,500 – 5,000 t hydraulic press | Shafts to 8 m, blocks and discs to 8,000 kg single piece | | Ring rolling | 3 m and 6 m radial-axial ring mills | Seamless rolled rings 200 – 2,500 mm OD, wall ≥ 30 mm | | Heat treatment | Bogie-hearth furnaces with ±5 °C uniformity, water quench tank | Solution anneal 1,121 °C with charted quench delay under 60 seconds | | NDT (ultrasonic) | Ultrasonic flaw detection | EN 10228-3 · SEP 1921 · ASTM A388, acceptance class per order | | NDT (surface) | Dye penetrant (nickel alloys are non-magnetic, so MPI does not apply) | EN ISO 3452 acceptance per order | | Lab (chemistry) | Optical emission spectrometer, combustion C/S analyser | Full elemental analysis; carbon and sulfur to the low limits this grade requires | | Lab (mechanical) | Universal testing machine, Charpy impact tester, hardness testers | Tensile, impact and hardness on coupons from the delivered heat; NACE hardness verification | | Lab (metallography) | Metallographic microscope | Grain size, intermetallic-phase check, macroetch for grain flow | | Corrosion testing | Accredited subcontract laboratory | ASTM G28 method A intergranular attack; ASTM G48 method A/B pitting and crevice | | Machining | CNC lathes, vertical borers, machining centres | Rough or finish machining to drawing, including sealing faces and bores | > On NC17D the single most informative document is the **heat-treatment chart showing the delay between furnace exit and water entry**. Our target is under 60 seconds on every piece. Combined with an ASTM G28 method A result, it is direct evidence that the delivered forging is free of grain-boundary intermetallic phase. Both are available on request at no extra charge for orders above 500 kg. ### NC17D Forging Weight Calculator *Interactive calculator. Run it on the web page: * Uses the NC17D density of 8.89 g/cm³ (0.321 lb/in³). The result is the **net finished weight**. The rough forging estimate adds a machining allowance of 25% for rings and discs and 20% for bars and blocks; real allowance depends on geometry, tolerance and surface finish. Maximum single-piece capability at Jiangyin Jiangnan Metal Co., Ltd. is 8,000 kg. ## 13. Standards, testing and certification NC17D orders at Jiangyin Jiangnan Metal Co., Ltd. are produced and certified against the specifications below. The product standard for forgings is normally **ASTM B564 / ASME SB-564**; the inspection-document type is normally **EN 10204 3.1**. - ASTM B564 / SB-564 - ASTM B574 / SB-574 - ASTM B575 / SB-575 - ASTM B622 - ASTM B366 · B462 - ASTM B472 - UNS N10276 - DIN 17744 · 2.4819 - VdTÜV Wbl. 400 - AFNOR NC17D - ISO NiMo16Cr15Fe6W4 - JIS NW0276 - NACE MR0175 / ISO 15156 - EN 10204 3.1 - EN 10204 3.2 - EN 10228-3 (UT) - SEP 1921 (UT) - ASTM A388 (UT) - ASTM G28 method A - ASTM G48 method A/B - ISO 9001:2015 ### What appears on the certificate - Heat number, with full ladle *and* product chemical analysis, including carbon and sulfur to the low limits this grade requires - Melting route (EAF + VOD + ESR, or VIM + VAR where specified) - Mechanical test results (tensile, 0.2% yield, elongation, hardness) on coupons from the delivered heat - **Solution-annealing record: temperature, hold time, quench medium and the furnace-to-quench delay** - Ultrasonic examination report to the ordered standard and acceptance class - ASTM G28 method A intergranular corrosion result, where ordered - NACE MR0175 / ISO 15156 hardness verification, where the part enters sour service - Dimensional inspection report and PMI (positive material identification), where ordered - Cross-listed equivalent designations: NC17D / UNS N10276 / W.Nr. 2.4819 / NiMo16Cr15W / NW0276 ### Quality gates and non-conformance handling Every NC17D order passes six mandatory hold points at which production cannot continue without QA sign-off: raw-material chemistry verification, forging temperature compliance, post-forging ultrasonic examination, **heat-treatment chart approval including quench delay**, mechanical and corrosion test acceptance, and final NDE plus dimensional inspection. Customer-witnessed hold points can be added at no charge. Any out-of-specification finding raises a formal non-conformance report within 24 hours, with root-cause analysis inside five working days and the proposed disposition sent to the customer before any rework is carried out. ## 14. How to specify an NC17D forging order NC17D carries two specification decisions that most grades do not: **the delivered condition has to be stated as solution annealed and quenched**, and **the corrosion acceptance test has to be named if it matters**. Neither is implied by the chemistry alone. The eight steps below remove the ambiguity that causes most disputes on this grade. 1. **Name the grade unambiguously.** Write "NC17D / UNS N10276 / W.Nr. 2.4819" rather than a brand name alone, so the certificate can cross-reference every applicable standard. 2. **State the product standard.** ASTM B564 / ASME SB-564 for forgings, B574 for rod and bar, B575 for plate. Name the revision in force at the contract date. 3. **Send the drawing.** Finished dimensions, machining allowance, tolerances, surface finish, and the required grain-flow direction for rings and shafts. 4. **Specify the delivery condition.** "Solution annealed at 1,121 °C ± 15 °C, water quenched", and require the chart. This is the single most important line on the order. 5. **State the corrosion acceptance test.** ASTM G28 method A for intergranular attack is the usual choice; add ASTM G48 pitting or crevice testing where chloride service justifies it. 6. **Define non-destructive examination.** UT to EN 10228-3, SEP 1921 or ASTM A388 with the acceptance class stated. Note that magnetic particle inspection does not apply, because the alloy is non-magnetic. Use dye penetrant on machined surfaces. 7. **Specify certification and sour-service compliance.** EN 10204 3.1 or 3.2, naming the third party for 3.2; state NACE MR0175 / ISO 15156 and the hardness cap where the part enters sour service. 8. **Give quantity, delivery and terms.** Pieces, required date, destination port and Incoterms, so the quotation covers the full delivered cost. ### Recommended drawing callout **Table 12. Copy-ready NC17D material callout for engineering drawings** | | | |---|---| | MATERIAL | NC17D / UNS N10276 / W.Nr. 2.4819 (also satisfies NiMo16Cr15W, ISO NiMo16Cr15Fe6W4, JIS NW0276) | | PRODUCT STANDARD | ASTM B564 / ASME SB-564, latest revision | | CHEMISTRY LIMIT | C ≤ 0.010% and Si ≤ 0.08% MANDATORY Product analysis to be reported, not ladle analysis alone | | CONDITION | Solution annealed 1121 °C ± 15 °C, WATER QUENCHED Furnace-to-quench delay ≤ 60 s. Heat-treatment chart to be supplied | | CORROSION TEST | ASTM G28 method A, rate ≤ 1.0 mm/y, no intergranular attack (add ASTM G48 method B, CCT ≥ 50 °C, for chloride service) | | FORM | Seamless rolled ring, circumferential grain flow Machined-from-plate substitution NOT permitted | | NDE | UT per EN 10228-3, quality class 3 Surface PT per EN ISO 3452. MPI not applicable (non-magnetic) | | SOUR SERVICE | NACE MR0175 / ISO 15156 compliant, hardness ≤ 100 HRB (delete if not applicable) | | CERTIFICATION | EN 10204 3.1 mill certificate (3.2 with third-party witness where stated) | | MARKING | Heat number + grade + drawing number, vibro-etched on a non-functional surface. No steel stamping on sealing faces | ## 15. Top 10 mistakes when ordering NC17D forgings 1. **Accepting the certificate without the quench record.** Chemistry alone proves nothing on this grade. A slowly cooled forging has correct chemistry and sensitised grain boundaries. 2. **Ordering to the legacy 0.02% carbon limit.** Modern NC17D is C ≤ 0.010%. Double the carbon reintroduces the heat-affected-zone problem the grade was invented to solve. 3. **Assuming it is a high-temperature alloy.** Sustained service above about 650 °C precipitates mu and P phases and destroys corrosion resistance. Use alloy 625 or Haynes 230 for hot structural work. 4. **Specifying a stress-relief soak.** There is no valid low-temperature stress relief for NC17D. Any soak in the 650–1,090 °C range sensitises it. 5. **Accepting an "aged" or "precipitation hardened" NC17D certificate.** The alloy cannot be age hardened. Such a certificate indicates either the wrong grade or a fabricated document. 6. **Confusing NC17D with alloy C (N10002) or with NC22DNb.** Legacy AFNOR names in this family look similar and the substitution fails in service. 7. **Using NC17D in strongly oxidising acid.** Hot concentrated nitric acid and high-temperature ferric chloride need the higher chromium of C-22, alloy 59 or C-2000. 8. **Specifying magnetic particle inspection.** NC17D is non-magnetic; MPI cannot work. Specify dye penetrant instead, or the order will stall at inspection. 9. **Buying a ring machined from plate.** Exposed end grain at the bore and faces is a preferential corrosion initiation site in chloride service. Specify the forged and rolled route. 10. **Under-costing the machining.** NC17D machines at roughly 15–20% of the productivity of 316L. Budget the tooling, or buy nearer to net shape. ### NC17D RFQ Text Generator *Interactive calculator. Run it on the web page: * ## Request an NC17D quotation Send a drawing or a specification and we respond within 24 hours with price, lead time and confirmation of the applicable standards. For chloride or acid service, state the medium, concentration, temperature and pH. These change how we plan the heat, the anneal and the acceptance testing. **Jiangyin Jiangnan Metal Co., Ltd.** · Open-Die Forging Factory · No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China Email · Telephone +86-189-2135-9659 · WhatsApp ## 16. Glossary ## 17. Frequently asked questions: NC17D / UNS N10276 ### What is NC17D? NC17D is the AFNOR (French) designation for a nickel-molybdenum-chromium alloy with a tungsten addition, containing nominally 57% nickel, 16% molybdenum, 16% chromium, 5% iron and 4% tungsten, with carbon held to 0.010% maximum. The same alloy is designated UNS N10276 in the United States, W.Nr. 2.4819 / NiMo16Cr15W in Germany and ISO NiMo16Cr15Fe6W4 internationally, and is sold under the trade name Hastelloy® C-276 by its originator. It is a solid-solution alloy that is not hardenable by heat treatment, and it is specified where a component must resist both oxidising and reducing acids, chloride pitting, crevice attack and chloride stress-corrosion cracking at the same time. Jiangyin Jiangnan Metal Co., Ltd. produces NC17D in forged form: seamless rolled rings, forged rings, flanges, shafts, discs, sleeves, bushings, tube sheets and bars. ### Are NC17D, UNS N10276, 2.4819, NiMo16Cr15W and alloy C-276 the same material? Yes. All of these designations describe the same nominal Ni-16Mo-16Cr-4W chemistry. NC17D is the AFNOR French designation, UNS N10276 is the American Unified Numbering System number, W.Nr. 2.4819 with the name NiMo16Cr15W is the German Werkstoff designation under DIN 17744, NiMo16Cr15Fe6W4 is the ISO name, NW0276 is the JIS number and Ch-N65MV is the GOST equivalent. Hastelloy® C-276 is the registered trade name of Haynes International, Inc. and Nicrofer® 5716 hMoW is the VDM Metals brand for the same chemistry. Jiangyin Jiangnan Metal Co., Ltd. supplies the generic grade, correctly described as NC17D / UNS N10276 / W.Nr. 2.4819, with every applicable equivalent cross-listed on the EN 10204 material certificate. We are not affiliated with, sponsored by or endorsed by any of those trademark holders. ### What is the chemical composition of NC17D? NC17D contains 14.5-16.5% chromium, 15.0-17.0% molybdenum, 3.0-4.5% tungsten and 4.0-7.0% iron, with nickel as the balance at roughly 57%. Maximum limits apply to cobalt at 2.5%, manganese at 1.0%, copper at 0.50%, vanadium at 0.35%, silicon at 0.08% and carbon at 0.010%, with phosphorus and sulfur held to residual levels. The very low carbon and silicon are the defining feature of the grade: they suppress carbide and intermetallic precipitation at grain boundaries during welding, which is why NC17D can be used in the as-welded condition without a post-weld solution anneal. Some older AFNOR-era NC17D drawings still show carbon at 0.02% maximum; modern practice and ASTM B564 / B574 both cap it at 0.010%, and forgings should be ordered to the tighter limit. ### What is the density of NC17D? The density of NC17D (UNS N10276 / 2.4819) is 8.89 g/cm³, equivalent to 0.321 lb/in³. Use this figure to convert a finished part volume into forging weight for a request for quotation, then add a machining allowance of roughly 25% for rings and discs and 20% for bars and blocks. The forging weight calculator on this page performs both steps. Maximum single-piece weight at Jiangyin Jiangnan Metal Co., Ltd. is 8,000 kg. ### What are the mechanical properties of NC17D forgings? In the solution-annealed condition, ASTM B574 requires a minimum tensile strength of 690 MPa (100 ksi), a minimum 0.2% offset yield strength of 283 MPa (41 ksi) and minimum elongation of 40% for rod and bar. Typical measured values on annealed product are considerably higher: around 785 MPa tensile, 365 MPa yield and 59% elongation, with hardness near 86-88 HRB. The alloy is exceptionally tough, with Charpy V-notch impact energy of roughly 479 J at room temperature and 519 J at -196 °C, so it retains ductility in cryogenic service. NC17D is a solid-solution alloy and cannot be strengthened by ageing; the only route to higher strength is cold work, which reduces resistance to stress-corrosion cracking and is therefore normally removed by re-annealing. ### What is the PREN of NC17D? Using the standard formula PREN = %Cr + 3.3 × %Mo, NC17D has a pitting resistance equivalent number of approximately 68 at nominal composition (16% Cr, 16% Mo). Where the tungsten contribution is counted, using PREN = %Cr + 3.3 × (%Mo + 0.5 × %W), the figure rises to approximately 75. For comparison, 316L stainless steel sits near 24 and 6% molybdenum super-austenitic 254 SMO near 43. The practical consequence is measurable: in acidified 6% ferric chloride per ASTM G48, the critical pitting temperature of NC17D exceeds 150 °C and its critical crevice temperature is about 55 °C, against 15 °C and 0 °C respectively for 316L. ### At what temperature is NC17D forged? NC17D is hot forged from a start temperature of approximately 1,232 °C (2,250 °F) down to a finish temperature of approximately 954 °C (1,750 °F). The working window is narrow by comparison with austenitic stainless steel, and the alloy is more sensitive to strain and strain rate, so moderate reductions with frequent reheating give the best result. Forging below the finish temperature causes cracking and leaves residual cold work that must be removed. Every hot-worked NC17D forging is re-annealed after forming to restore corrosion resistance and ductility, because the mu and P intermetallic phases that precipitate between roughly 650 °C and 1,090 °C during slow cooling are the mechanism behind most in-service corrosion failures of this grade. ### How is NC17D solution annealed? NC17D is solution annealed at 1,121 °C (2,050 °F), held for 10 to 30 minutes according to section thickness, and then water quenched. Rapid air cooling is acceptable only for sections thinner than about 10 mm. The commercial temperature band quoted by European mills is 1,080-1,135 °C. The purpose of the treatment is to redissolve carbides and the mu and P intermetallic phases and to freeze the alloy in a single-phase austenitic condition on cooling, which is what delivers its corrosion resistance. Slow cooling through the 650-1,090 °C range re-precipitates those phases at grain boundaries and sensitises the material, so quench rate matters as much as soak temperature. NC17D is re-annealed after all hot forming, and after any cold forming that produces outer-fibre elongation of 7% or more. ### What corrosion resistance does NC17D offer? NC17D resists both oxidising and reducing media, which few alloys manage together, because chromium handles the oxidising side and molybdenum with tungsten handles the reducing side. It withstands hot contaminated mineral acids, sulfuric acid across the full concentration range at moderate temperature, hydrochloric acid up to about 10% at 40 °C, wet chlorine gas, hypochlorite, chlorine dioxide, formic and acetic acids, acetic anhydride, seawater and brine. In ASTM G48 acidified 6% ferric chloride the critical pitting temperature exceeds 150 °C and the critical crevice temperature is about 55 °C. In boiling 45% magnesium chloride per ASTM G36, U-bend specimens showed no stress-corrosion cracking after 1,008 hours. In 180-day flowing-seawater crevice tests the alloy showed no attack at any test site. It is also qualified for sour service under NACE MR0175 / ISO 15156. ### What forged products are available in NC17D? Jiangyin Jiangnan Metal Co., Ltd. produces NC17D as seamless rolled rings from 200 mm to 2,500 mm outside diameter, forged rings, forged flanges to 1,500 mm outside diameter, forged round bars from 25 mm to 500 mm diameter, forged discs and blanks to 1,800 mm diameter, forged shafts and spindles to 8,000 mm length, forged sleeves and bushings, forged tube sheets to 2,000 mm diameter, forged tubes and hollows, forged valve bodies, stems and seat rings, forged blocks to 8,000 kg single-piece weight, and near-net-shape parts made to customer drawings. All forms are supplied solution annealed and water quenched, with EN 10204 3.1 certification as standard. ### Who manufactures NC17D forged rings and flanges? Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China, that manufactures NC17D (UNS N10276 / W.Nr. 2.4819) forged rings, seamless rolled rings, flanges, shafts, discs, sleeves, tube sheets and bars to customer drawings. The plant operates 1, 3, 5 and 9 tonne forging hammers, a 4,500-5,000 tonne hydraulic press and 3 m and 6 m radial-axial ring rolling mills, and employs approximately 460 people including 9 senior engineers and 32 intermediate engineers. EN 10204 3.1 certification is supplied as standard and 3.2 with third-party witness on request. Contact +86-189-2135-9659 or sales@steelforgepieces.com. ### What is the difference between NC17D (C-276) and Hastelloy C-22? Both are nickel-chromium-molybdenum alloys, but the balance differs. NC17D / C-276 runs about 16% chromium, 16% molybdenum and 4% tungsten, while C-22 runs about 22% chromium, 13% molybdenum and 3% tungsten. The higher chromium of C-22 gives better performance in strongly oxidising conditions such as hot nitric acid, oxidising chlorides and ferric or cupric chloride, and it is more tolerant of weld heat-affected zones. The higher molybdenum and tungsten of NC17D give better performance in reducing conditions such as hydrochloric and dilute sulfuric acid, and NC17D remains the more widely stocked and more economical of the two. Where the process alternates between oxidising and reducing states, C-22 or alloy 59 is often preferred; where the environment is reducing and chloride-bearing, NC17D is usually the right choice. ### What is the difference between NC17D and Inconel 625? Alloy 625 (UNS N06625) contains about 21% chromium, 9% molybdenum and 3.5% niobium, and is strengthened by the niobium addition, whereas NC17D contains about 16% chromium and 16% molybdenum with no niobium and relies on solid-solution strengthening alone. Alloy 625 is stronger and better suited to elevated-temperature structural service, and it is cheaper. NC17D is substantially more resistant to localised corrosion: its critical pitting temperature in acidified 6% ferric chloride exceeds 150 °C against about 100 °C for alloy 625, and it holds up far better in hydrochloric acid and reducing chloride environments. Choose alloy 625 for strength and high-temperature service, NC17D where the governing requirement is corrosion in a wet, chloride-bearing or acidic process. ### Can NC17D be welded? Yes, and it is one of the few highly corrosion-resistant nickel alloys that can normally be used in the as-welded condition without a post-weld solution anneal. That property is a direct result of the 0.010% maximum carbon and 0.08% maximum silicon limits, which suppress grain-boundary carbide precipitation in the heat-affected zone. NC17D is welded by GTAW (TIG), GMAW (MIG) and SMAW (stick) using matching filler: ERNiCrMo-4 bare wire to AWS A5.14 or ENiCrMo-4 covered electrodes to AWS A5.11. Keep heat input low, interpass temperature below about 100 °C, and joint faces clean and free of sulfur, lead and other low-melting-point contamination. Where a weldment will see an especially aggressive service or has undergone heavy restraint, a full solution anneal at 1,121 °C followed by a rapid quench restores the optimum condition. ### Is NC17D magnetic? No. NC17D is a single-phase, face-centred-cubic austenitic alloy and is effectively non-magnetic, with a relative magnetic permeability of about 1.0002 measured at 15.9 kA/m. It has no magnetic transformation on cooling and cannot be hardened by heat treatment. A reading noticeably above 1.002 on delivered material normally indicates surface contamination by ferritic tooling or the presence of a second phase, and should be investigated before the part is accepted. ### What certification is supplied with NC17D forgings? EN 10204 3.1 mill certification is supplied as standard, listing heat number, full ladle and product chemical analysis, mechanical test results on coupons from the delivered heat, solution-annealing records including temperature, hold time and quench method, ultrasonic examination results and a dimensional report. EN 10204 3.2 certification countersigned by Lloyd's Register, DNV, Bureau Veritas, ABS, SGS or TÜV is available on request. Ultrasonic testing is performed to EN 10228-3, SEP 1921 or ASTM A388 as the order specifies. Intergranular corrosion testing to ASTM G28 method A, pitting and crevice testing to ASTM G48, positive material identification and NACE MR0175 / ISO 15156 hardness verification can all be added to the certificate. ### What is the lead time for NC17D forgings? Standard NC17D forgings in the solution-annealed condition typically ship 8 to 12 weeks from order confirmation. Large single pieces above 3 tonnes, orders requiring EN 10204 3.2 third-party witnessed inspection, and orders with added corrosion testing extend to 12-16 weeks. Quotation is issued within 24 hours of receiving a drawing or specification at sales@steelforgepieces.com. ### Where is NC17D used? NC17D is specified across chemical and petrochemical processing (reactors, columns, heat-exchanger tube sheets, agitator shafts, pump and valve components), flue-gas desulfurisation (scrubber internals, ducting, quench components), pulp and paper bleaching (chlorine dioxide and hypochlorite service), sour oil and gas (wellhead and Christmas-tree components, subsea hardware, downhole tools qualified to NACE MR0175 / ISO 15156), pharmaceutical and fine-chemical plant, waste incineration and pollution control, marine and offshore seawater systems, and phosphoric and sulfuric acid production. In forged form the most common items are seamless rolled rings, flanges, tube sheets, valve bodies and seat rings, pump and agitator shafts, and heavy discs. ## 18. Technical references Chemistry, physical, mechanical, corrosion and heat-treatment data on this page are drawn from the published standards and producer datasheets listed below. Test results reported on our own material certificates are independent and traceable to calibrated laboratory equipment. 1. ASTM B564, *Standard Specification for Nickel Alloy Forgings*, ASTM International, West Conshohocken, PA. 2. ASTM B574, *Standard Specification for Low-Carbon Nickel-Molybdenum-Chromium, Low-Carbon Nickel-Chromium-Molybdenum and related Alloy Rod*, ASTM International. 3. ASTM B575, *Standard Specification for Low-Carbon Nickel Alloy Plate, Sheet and Strip*, ASTM International. 4. ASTM B622, *Standard Specification for Seamless Nickel and Nickel-Cobalt Alloy Pipe and Tube*, ASTM International. 5. ASTM B462, *Standard Specification for Forged or Rolled Corrosion-Resistant Nickel Alloy Pipe Flanges and Fittings for Pressure Service*, ASTM International. 6. ASTM G28, *Standard Test Methods for Detecting Susceptibility to Intergranular Corrosion in Wrought Nickel-Rich, Chromium-Bearing Alloys*, ASTM International. 7. ASTM G48, *Standard Test Methods for Pitting and Crevice Corrosion Resistance of Stainless Steels and Related Alloys by Use of Ferric Chloride Solution*, ASTM International. 8. ASTM G36, *Standard Practice for Evaluating Stress-Corrosion-Cracking Resistance of Metals and Alloys in a Boiling Magnesium Chloride Solution*, ASTM International. 9. ASTM A388, *Standard Practice for Ultrasonic Examination of Steel Forgings*, ASTM International. 10. DIN 17744, *Wrought nickel alloys with molybdenum and chromium — chemical composition*, Deutsches Institut für Normung. 11. VdTÜV Werkstoffblatt 400, *NiMo16Cr15W (2.4819)*, Verband der TÜV. 12. EN 10204:2004, *Metallic products — Types of inspection documents*, CEN, Brussels. 13. EN 10228-3, *Non-destructive testing of steel forgings, Part 3: Ultrasonic testing*, CEN. 14. SEP 1921, *Ultrasonic testing of steel forgings*, Stahl-Eisen-Prüfblatt. 15. NACE MR0175 / ISO 15156, *Petroleum and natural gas industries — Materials for use in H₂S-containing environments in oil and gas production*. 16. AWS A5.14 (ERNiCrMo-4) and AWS A5.11 (ENiCrMo-4), *Specifications for nickel and nickel-alloy welding consumables*, American Welding Society. 17. Haynes International, Inc., published technical datasheet for HASTELLOY® C-276 alloy (UNS N10276): physical properties, tensile and impact data, ASTM G48 and G36 results, forging and annealing practice. 18. VDM Metals GmbH, published datasheet for VDM® Alloy C-276 / Nicrofer® 5716 hMoW: designations, standards cross-reference and composition limits. 19. ASM Specialty Handbook: *Nickel, Cobalt and Their Alloys*, J.R. Davis (ed.), ASM International. 20. ASM Handbook, Volume 13B: *Corrosion: Materials*, ASM International; sections on nickel-chromium-molybdenum alloys. 21. Aylor, D.M. et al., *Crevice corrosion behaviour of candidate naval ship seawater valve materials*, Paper No. 329, CORROSION 99, NACE International, 1999; flowing-seawater crevice data. Standards cited are the revisions known to us at the time of the last page review. For procurement, always reference the revision in force at the contract date. All trademarks referenced belong to their respective owners. ## Related grades and forged products - [Alloy C-276](https://www.steelforgepieces.com/Nickel-Alloy/Hastelloy-C-276.html) - [Alloy C-22](https://www.steelforgepieces.com/Nickel-Alloy/Hastelloy-C-22.html) - [Alloy C-2000](https://www.steelforgepieces.com/Nickel-Alloy/Hastelloy-C-2000.html) - [Alloy C-4](https://www.steelforgepieces.com/Nickel-Alloy/Hastelloy-C-4.html) - [Alloy 59](https://www.steelforgepieces.com/Nickel-Alloy/Alloy-59.html) - [Alloy B-2](https://www.steelforgepieces.com/Nickel-Alloy/Hastelloy-B-2.html) - [Alloy B-3](https://www.steelforgepieces.com/Nickel-Alloy/Hastelloy-B-3.html) - [Alloy G-3](https://www.steelforgepieces.com/Nickel-Alloy/Hastelloy-G-3.html) - [Alloy X](https://www.steelforgepieces.com/Nickel-Alloy/Hastelloy-X.html) - [Inconel 625](https://www.steelforgepieces.com/Nickel-Alloy/Inconel-625.html) - [Inconel 600](https://www.steelforgepieces.com/Nickel-Alloy/Inconel-600.html) - [Incoloy 825](https://www.steelforgepieces.com/Nickel-Alloy/Incoloy-825.html) - [Incoloy 925](https://www.steelforgepieces.com/Nickel-Alloy/Incoloy-925.html) - [Monel 400](https://www.steelforgepieces.com/Nickel-Alloy/Monel-400.html) - [Alloy 602](https://www.steelforgepieces.com/Nickel-Alloy/Alloy-602.html) - [Forged & rolled rings](https://www.steelforgepieces.com/Forging-Rings/Forging-Ring.html) - [Forged disks](https://www.steelforgepieces.com/Forged-Disks/Forged-Disk.html) - [Forged tubes](https://www.steelforgepieces.com/Forging-Tubes/Forging-Tube.html) - [Forged spindles](https://www.steelforgepieces.com/Forging-Spindles/Forging-Spindle.html) - [Open die forgings](https://www.steelforgepieces.com/Forging-Parts/Open-Die-Forging-Parts.html) ## 19. Cite this page This datasheet is maintained by the metallurgical engineering team at **Jiangyin Jiangnan Metal Co., Ltd.** and is free to quote, reference or link to. If you use the data in a specification, report or article, please attribute it as follows. This file is the Markdown copy of the HTML datasheet at , which also carries the six interactive calculators referenced above. **Source of record:** Jiangyin Jiangnan Metal Co., Ltd., open-die forging factory, No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China · [+86-189-2135-9659](tel:+8618921359659) · [sales@steelforgepieces.com](mailto:sales@steelforgepieces.com) · [www.steelforgepieces.com](https://www.steelforgepieces.com/)