# UNS N10675 Forgings: Open-Die Forged Hastelloy B-3 Seamless rolled rings, flanges, bars, shafts, discs, sleeves and tube sheets in UNS N10675, also written UNS N010675, forged to ASTM B564 by Jiangyin Jiangnan Metal Co., Ltd. in Jiangyin, Jiangsu, China. **Source:** https://www.steelforgepieces.com/Nickel-Alloy/UNS-N010675.html **Supplier:** Jiangyin Jiangnan Metal Co., Ltd., open-die forging factory **Address:** No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China **Phone:** +86 189 2135 9659 **Email:** sales@steelforgepieces.com **Last reviewed:** 29 August 2026 --- ## Key facts | Item | Value | | --- | --- | | UNS number | N10675 (often typed N010675) | | Common name | Hastelloy B-3 / Alloy B-3 | | Werkstoff number | 2.4600 | | Alloy family | Nickel-molybdenum (Ni-Mo) | | Nickel | 65.0 % min | | Molybdenum | 27.0 to 32.0 % | | Forging specification | ASTM B564 | | Melting route | EAF + VOD + ESR | | Heat treatment | Solution annealed | | Tensile strength, 21 C | 862 MPa (125.0 ksi) | | 0.2 % yield, 21 C | 418 MPa (60.6 ksi) | | Certification | EN 10204 3.1 / 3.2 | --- ## What is UNS N10675? UNS N10675 is a nickel-molybdenum alloy containing a minimum of 65 % nickel and 27 to 32 % molybdenum, sold commercially as Hastelloy B-3. It resists pitting, general corrosion and stress-corrosion cracking in reducing media such as hydrochloric acid, sulfuric acid, acetic acid and phosphoric acid. Compared with the older alloy B-2, it holds up much better under welding and thermal cycling, because the low iron, chromium and carbon levels slow down the formation of embrittling intermetallic phases. **A note on the designation.** The correct UNS number is N10675, with a single zero after the N. N010675, with two, is a variant that turns up regularly on drawings, enquiries and supplier catalogues around the world. Both point to the same alloy, and Jiangyin Jiangnan Metal quotes and supplies against either spelling. ### Designation cross-reference | System | Designation | Note | | --- | --- | --- | | UNS | N10675 | Correct form | | UNS variant | N010675 | Common typing variant of the same alloy | | Trade name | Hastelloy B-3 | Haynes International trademark | | Generic | Alloy B-3 | Non-trademarked usage | | Werkstoff | 2.4600 | German material number | | DIN | NiMo29Cr | Chemical short name | | ASTM forgings | B564 | Nickel alloy forgings | | ASTM bar | B335 | Ni-Mo alloy rod and bar | --- ## Chemical composition of UNS N10675 UNS N10675 runs 65 % minimum nickel, 27.0 to 32.0 % molybdenum, 1.0 to 3.0 % chromium and 1.0 to 3.0 % iron, with carbon held to 0.01 % maximum. That low carbon level, together with the restricted chromium and iron, is what keeps alloy B-3 stable at temperature. Composition limits in weight percent, per ASTM B564 and ASTM B335. Nickel is the balance. | Limit | Ni | Mo | Cr | Fe | Co | Mn | Al | Ti | Cu | Si | Nb | V | C | P | S | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | Min | 65.0 | 27.0 | 1.0 | 1.0 | - | - | - | - | - | - | - | - | - | - | - | | Max | bal. | 32.0 | 3.0 | 3.0 | 3.0 | 3.0 | 0.5 | 0.2 | 0.2 | 0.10 | 0.2 | 0.2 | 0.01 | 0.03 | 0.01 | Each heat is analysed before forging and the ladle analysis is reported on the material certificate. Where a project calls for tighter limits than the standard allows, state them on the enquiry and Jiangyin Jiangnan Metal will confirm before the heat is melted. --- ## Mechanical properties of UNS N10675 Solution annealed UNS N10675 gives roughly 862 MPa (125.0 ksi) tensile strength, 418 MPa (60.6 ksi) yield strength at 0.2 % offset, and 53 % elongation at room temperature. Strength drops and ductility rises as the service temperature goes up. Typical tensile properties of solution annealed material. Metric figures are converted from the ksi values. | Property | 21 C / 70 F | 93 C / 200 F | | --- | --- | --- | | Ultimate tensile strength | 862 MPa (125.0 ksi) | 832 MPa (120.7 ksi) | | 0.2 % offset yield strength | 418 MPa (60.6 ksi) | 381 MPa (55.3 ksi) | | Elongation in 4D | 53.4 % | 56.9 % | What a finished forging actually delivers depends on section size, forging reduction and how fast it is quenched. Jiangyin Jiangnan Metal tests from a prolongation or a sacrificial ring taken at the heaviest section and reports the real numbers on the certificate. --- ## UNS N10675 forged product forms Jiangyin Jiangnan Metal produces UNS N10675 as seamless rolled rings, forged rings, flanges, round bars, shafts, discs, sleeves, bushings, hollow bars, forged tubes, tube sheets and valve components, all open-die forged and machined to customer drawing. | Product form | Size range | Unit weight | Typical use | | --- | --- | --- | --- | | Seamless rolled rings | OD 200 to 3000 mm | up to 5000 kg | Reactor shells, flanged joints, bearing races | | Forged flanges | DN 15 to DN 1200 | up to 2000 kg | Piping, heat exchangers, pressure vessels | | Round bars | dia. 20 to 800 mm | up to 3000 kg | Valve stems, fasteners, machined parts | | Shafts and spindles | dia. 60 to 700 mm, length to 6000 mm | up to 4000 kg | Chemical pumps, agitators, plunger pumps | | Discs and blanks | dia. 100 to 2000 mm | up to 4000 kg | Tube sheets, blind flanges, gear blanks | | Sleeves and bushings | OD 80 to 1200 mm | up to 1500 kg | Wear surfaces, subsea components | | Hollow bars and forged tubes | OD 100 to 1000 mm | up to 2500 kg | Heat exchanger nozzles, pressure parts | | Valve bodies and seat rings | To drawing | up to 3000 kg | Ball, gate, globe, check and plug valves | Confirm final dimensions on enquiry; larger sizes may be possible. --- ## How UNS N10675 forgings are produced Every UNS N10675 forging goes through the same five stages: EAF and VOD melting, ESR remelting, open-die forging or ring rolling, solution annealing with a rapid quench, then ultrasonic testing and certification. 1. **Melting, EAF and VOD.** Electric arc furnace melting followed by vacuum oxygen decarburisation brings carbon down to the 0.01 % maximum that alloy B-3 needs. 2. **Remelting, ESR.** Electroslag remelting tightens the ingot structure, cuts sulfur and non-metallic inclusions, and evens out the chemistry through the section. This matters most on the heavy sections used for reactor and valve parts. 3. **Forging, open die or ring rolling.** The ingot is upset and drawn under the press to reach the required forging ratio, then either open-die forged to shape or expanded on the ring mill for seamless rolled rings. Finish forging temperature is controlled to keep grain size even. 4. **Heat treatment, solution anneal.** Forgings are solution annealed and quenched fast to dissolve carbides and intermetallic phases and bring corrosion resistance back. Slow cooling through the 700 to 900 C range is avoided. 5. **Inspection and certification.** Ultrasonic testing to EN 10228-3, SEP 1921 or ASTM A388, plus chemical analysis, tensile testing and dimensional inspection. Certificates are issued to EN 10204 3.1, or 3.2 when third-party witness is required. --- ## Standards, testing and certification UNS N10675 forgings are supplied to ASTM B564 with EN 10204 3.1 or 3.2 certification, ultrasonically tested to EN 10228-3, SEP 1921 or ASTM A388 as specified on the order. - **ASTM B564**, nickel alloy forgings. The governing specification for N10675 rings, flanges, discs and shafts. - **ASTM B335**, nickel-molybdenum alloy rod and bar. Applied to N10675 bar stock. - **EN 10228-3, SEP 1921 and ASTM A388**, ultrasonic examination. State the acceptance class you need on the enquiry. - **EN 10204 3.1**, material certificate issued by our own authorised inspection representative, independent of the production department. - **EN 10204 3.2**, certificate countersigned by a third-party inspection body such as TUV, SGS, BV or Lloyd's Register. Arranged on request. - **Optional testing:** PMI, hardness survey, Charpy impact, intergranular corrosion testing to ASTM G28, grain size to ASTM E112, and macro or micro examination. --- ## Where UNS N10675 forgings are used UNS N10675 forgings get specified wherever reducing acids attack stainless steel: hydrochloric acid plants, sulfuric acid service, acetic and phosphoric acid production, pharmaceutical reactors and pickling lines. | Industry | Forged components | Service condition | | --- | --- | --- | | Chemical processing | Reactor shell rings, flanges, nozzles, agitator shafts | Hydrochloric and sulfuric acid at concentration and temperature | | Pressure vessels and heat exchangers | Tube sheets, forged tubes, shell flanges, blind discs | Shell and tube exchangers, air receivers, preheaters | | Valves and flow control | Valve bodies, seat rings, stems, plugs, blocks | Ball, gate, globe, check and plug valves in acid service | | Pumps and rotating equipment | Pump shafts, spindles, sleeves, wear rings, impeller blanks | Chemical pumps, plunger pumps, compressors | | Oil, gas and subsea | Bushings, sleeves, discs, wellhead and Christmas tree parts | Sour service, deepwater production systems | | Pharmaceutical and biochemistry | Crystalliser parts, forged nozzles, process module fittings | Acetic and phosphoric acid, high purity duty | | Pulp, paper and metallurgy | Rolls, wheels, manifolds, pickling line hardware | Digesters, bleaching plants, acid regeneration | --- ## UNS N10675 compared with B-2 and C-276 Pick N10675 over N10665 (B-2) when the part will be welded or thermally cycled, and over N10276 (C-276) when the medium is strongly reducing and free of oxidising species. Where oxidisers or chlorides are present, C-276 is the better choice. | Property | N10675 (B-3) | N10665 (B-2) | N10276 (C-276) | | --- | --- | --- | --- | | Nominal Mo | 28 % | 28 % | 16 % | | Nominal Cr | 1.5 % | under 1 % | 16 % | | Reducing acids, HCl and H2SO4 | Excellent | Excellent | Good | | Oxidising media | Poor | Poor | Excellent | | Thermal stability | High | Limited, beta phase forms | High | | Weld fabrication | Routine | Sensitive to heat input | Routine | Jiangyin Jiangnan Metal forges all three, so a material change during design review does not mean changing supplier. --- ## Frequently asked questions **Is UNS N010675 the same as UNS N10675?** Yes. The correct UNS designation is N10675, with one zero after the N. N010675 is a variant that turns up regularly on drawings, enquiries and supplier catalogues. Both refer to the same nickel-molybdenum alloy, sold commercially as Hastelloy B-3. **What is UNS N10675 alloy?** UNS N10675 is a nickel-molybdenum alloy with 65 % minimum nickel and 27 to 32 % molybdenum, sold commercially as Hastelloy B-3. It resists pitting, general corrosion and stress-corrosion cracking in reducing media such as hydrochloric and sulfuric acid. Its low iron, chromium and carbon levels slow down the formation of embrittling intermetallic phases, so it survives welding and thermal cycling better than alloy B-2. **Which standard covers UNS N10675 forgings?** ASTM B564 is the specification for nickel alloy forgings and covers UNS N10675 forged rings, flanges, discs and shafts. Jiangyin Jiangnan Metal supplies N10675 forgings to ASTM B564, with material certificates issued to EN 10204 3.1 or, where a third party is required, EN 10204 3.2. **How is UNS N10675 melted and heat treated?** Jiangyin Jiangnan Metal melts UNS N10675 by EAF plus VOD, then remelts by ESR to improve cleanliness and chemical homogeneity. Forgings are solution annealed and rapidly quenched, which puts carbides and intermetallic phases back into solution and restores corrosion resistance. **What product forms of UNS N10675 can be forged?** Jiangyin Jiangnan Metal produces UNS N10675 as seamless rolled rings, forged rings, flanges, round bars, shafts, discs, sleeves, bushings, hollow bars, forged tubes, tube sheets, valve bodies, valve seat rings and custom open-die forgings made to customer drawing. **What is the difference between Hastelloy B-2 and B-3?** Both are nickel-molybdenum alloys with roughly 28 % molybdenum, but B-3 holds up better to heat. B-2 (UNS N10665) forms beta phase and other intermetallics during welding and slow cooling through 700 to 900 C, which costs it ductility. B-3 (UNS N10675) is balanced to resist that transformation, so it takes thermal cycling better and is easier to fabricate. **How are UNS N10675 forgings inspected before shipment?** Each UNS N10675 forging is ultrasonically tested to EN 10228-3, SEP 1921 or ASTM A388 as agreed on the order, with chemical analysis, tensile testing and dimensional inspection recorded on the material certificate. Extra testing such as PMI, hardness survey, impact testing or corrosion testing to ASTM G28 can be added on request. **How do I request a quotation for UNS N10675 forgings?** Send the drawing or the finished dimensions, quantity, applicable specification and any NDT or certification requirements to sales@steelforgepieces.com, or call +86 189 2135 9659. Jiangyin Jiangnan Metal is at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China. --- ## Request a quotation Send a drawing or the finished dimensions and Jiangyin Jiangnan Metal will quote within one working day. Tell us the quantity, the specification, the NDT class and the certification level, and the quote will cover all of it. **Jiangyin Jiangnan Metal Co., Ltd.** No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China Phone: +86 189 2135 9659 Email: sales@steelforgepieces.com --- ## Related nickel alloy forgings - [Hastelloy B-3](https://www.steelforgepieces.com/Nickel-Alloy/Hastelloy-B-3.html) - [Hastelloy B-2](https://www.steelforgepieces.com/Nickel-Alloy/Hastelloy-B-2.html) - [Hastelloy B-4](https://www.steelforgepieces.com/Nickel-Alloy/Hastelloy-B-4.html) - [Hastelloy C-276](https://www.steelforgepieces.com/Nickel-Alloy/Hastelloy-C-276.html) - [Hastelloy C-22](https://www.steelforgepieces.com/Nickel-Alloy/Hastelloy-C-22.html) - [Hastelloy C-2000](https://www.steelforgepieces.com/Nickel-Alloy/Hastelloy-C-2000.html) - [Hastelloy X](https://www.steelforgepieces.com/Nickel-Alloy/Hastelloy-X.html) - [Alloy 59](https://www.steelforgepieces.com/Nickel-Alloy/Alloy-59.html) - [Alloy 602](https://www.steelforgepieces.com/Nickel-Alloy/Alloy-602.html) - [Inconel 625](https://www.steelforgepieces.com/Nickel-Alloy/Inconel-625.html) - [Inconel 718](https://www.steelforgepieces.com/Nickel-Alloy/Inconel-718.html) - [Incoloy 825](https://www.steelforgepieces.com/Nickel-Alloy/Incoloy-825.html) --- Technical data on this page is published by Jiangyin Jiangnan Metal Co., Ltd., an open-die forging factory in Jiangyin, Jiangsu, China. Figures are typical and do not replace the governing specification or a project material test report. Hastelloy is a registered trademark of Haynes International, Inc., used here only to identify the alloy grade.