# Alloy 602 CA Forgings **UNS N06025 / W.-Nr. 2.4633 / NiCr25FeAlY** Alloy 602 CA is a high-carbon nickel-chromium-iron alloy with additions of aluminium, yttrium, zirconium and titanium. Its oxidation limit in air is 1200 °C (2192 °F), one of the highest figures for any wrought nickel alloy in production. Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory in Jiangyin, Jiangsu Province, China. We forge Alloy 602 CA into seamless rolled rings, flanges, round bars, discs, shafts, sleeves, bushings and tube sheets to ASTM B564, supplied solution annealed with EN 10204 3.1 or 3.2 certificates. | | | |---|---| | UNS | N06025 | | Werkstoff | 2.4633 | | Max. in air | 1200 °C | | Forging spec | ASTM B564 | | Condition | Solution annealed | | Certificate | EN 10204 3.1 | Source page: https://www.steelforgepieces.com/Nickel-Alloy/ALLOY-602CA.html --- ## Key facts - **Identity.** Alloy 602 CA = UNS N06025 = W.-Nr. 2.4633 = NiCr25FeAlY. Sold under the trade names Nicrofer 6025 HT, INCONEL alloy 602 CA and RA 602 CA. - **Composition.** Nickel balance, 24.0-26.0 % Cr, 8.0-11.0 % Fe, 1.8-2.4 % Al, 0.15-0.25 % C, plus Y, Zr and Ti. No cobalt. - **Temperature limit.** 1200 °C in air. For pressure equipment, 982 °C under ASME Section VIII Div. 1 and 899 °C under Section I steam service (ASME Code Case 2359), and 1150 °C under VdTÜV Werkstoffblatt 540. - **Mechanical minimums, solution annealed.** Rm ≥ 680 MPa and A ≥ 30 % for sections up to 102 mm. Rp0.2 ≥ 270 MPa. - **Main reason it gets specified.** It holds up against carburisation and metal dusting where austenitic stainless and Alloy 800H do not, and its creep-rupture strength above 1000 °C is about 150 % that of Alloy 600. - **Forms we forge.** Seamless rolled rings, flanges, round bars, discs, shafts, sleeves, bushings, tube sheets, nozzles and valve components. - **Quality.** Ultrasonic testing to EN 10228-3, SEP 1921 or ASTM A388. Certificates to EN 10204 3.1 or 3.2, third-party witness on request. - **Manufacturer.** Jiangyin Jiangnan Metal Co., Ltd., No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China. sales@steelforgepieces.com, +86-189-2135-9659. --- ## Designations and equivalents This grade comes up in enquiries under a lot of different names. All of the following mean the same material, UNS N06025. | Item | Designation | |---|---| | UNS number | N06025 | | Werkstoff number | 2.4633 | | DIN designation | NiCr25FeAlY (also written NiCr25Fe10AlY) | | Common trade names | Nicrofer 6025 HT / VDM Alloy 602 CA (VDM Metals); INCONEL alloy 602 CA (Special Metals); RA 602 CA (Rolled Alloys) | | Forgings | ASTM B564 / ASME SB-564 | | Rod, bar and wire | ASTM B166 / ASME SB-166; DIN 17752 | | Plate, sheet and strip | ASTM B168 / ASME SB-168; DIN 17750 | | Seamless pipe and tube | ASTM B167 / ASME SB-167; DIN 17751 | | Pressure equipment approval | ASME Code Case 2359; VdTÜV Werkstoffblatt 540; DIN 17742 | | Matching weld filler | FM 602 / W.-Nr. 2.4649; AWS A5.14 ERNiCrFe-12; AWS A5.11 ENiCrFe-12 | Nicrofer, INCONEL and RA are registered trade names of VDM Metals, Special Metals Corporation and Rolled Alloys respectively. They appear here for material identification only. Jiangyin Jiangnan Metal Co., Ltd. is an independent forging manufacturer and is not affiliated with, endorsed by, or a licensee of those companies. --- ## Chemical composition Composition limits in weight percent, per ASTM B166 and B564 for UNS N06025. Each heat we forge carries its own analysis on the mill certificate. | Element | Symbol | Limits, wt % | |---|---|---| | Nickel | Ni | Balance | | Chromium | Cr | 24.0 - 26.0 | | Iron | Fe | 8.0 - 11.0 | | Aluminium | Al | 1.8 - 2.4 | | Carbon | C | 0.15 - 0.25 | | Titanium | Ti | 0.10 - 0.20 | | Yttrium | Y | 0.05 - 0.12 | | Zirconium | Zr | 0.01 - 0.10 | | Manganese | Mn | 0.15 max. | | Silicon | Si | 0.50 max. | | Copper | Cu | 0.10 max. | | Phosphorus | P | 0.020 max. | | Sulfur | S | 0.010 max. | The carbon is set high on purpose. On solution annealing it comes out as primary M23C6 and M7C3 chromium carbides on the grain boundaries, and those carbides carry the creep strength above 1000 °C. The aluminium and yttrium form an alumina layer under the chromia scale. That is what stops the scale spalling off under thermal cycling. --- ## Mechanical properties Minimum room-temperature values for forgings in the solution-annealed condition, per ASTM B564. | Property | Section D ≤ 102 mm | 102 < D ≤ 305 mm | |---|---|---| | Tensile strength Rm | ≥ 680 MPa | ≥ 580 MPa | | Yield strength Rp0.2 | ≥ 270 MPa | ≥ 270 MPa | | Elongation A | ≥ 30 % | ≥ 15 % | At temperature the alloy is specified on creep data rather than tensile data. Allowable stress values for code work are published in ASME Code Case 2359, and long-term creep-rupture values in VdTÜV Werkstoffblatt 540, for material solution annealed at 1220 °C with grain size of at least 70 µm. Above 1000 °C the creep-rupture strength runs about 150 % that of Alloy 600. One point to design around: in the solution-annealed condition this alloy loses rupture ductility between roughly 649 °C and 760 °C. If the part will sit in that band continuously, raise it at enquiry stage so the heat treatment can be set accordingly. --- ## Physical properties Typical values at 20 °C. | Property | Value | |---|---| | Density | 7.9 g/cm³ (0.285 lb/in³) | | Melting range | approx. 1340 - 1400 °C | | Modulus of elasticity | approx. 210 GPa | | Specific heat capacity | approx. 450 J/(kg·K) | | Thermal conductivity | approx. 10.5 W/(m·K) | | Mean thermal expansion, 20-1000 °C | approx. 16.5 × 10⁻⁶ /K | | Electrical resistivity | approx. 1.25 µΩ·m | | Crystal structure | Face-centred cubic, non-magnetic | Typical values, given for information. They are not guaranteed properties. Take design values from the governing code or the alloy producer's data sheet. Delivered properties are the ones stated on the mill certificate. --- ## Forging and heat treatment ### Hot working We forge Alloy 602 CA between about 1100 °C and 1220 °C and finish above roughly 1000 °C. It work-hardens fast, so we plan reheats instead of pushing a single heat too far, and we keep furnace atmospheres low in sulfur. ### Heat treatment After hot working, parts are solution annealed at about 1180-1220 °C and cooled quickly, water quenched or air cooled depending on whether the anneal is the last operation. Grain size of 70 µm or coarser is needed to reach the published creep values, so we set anneal temperature and soak time to hit that rather than following a fixed recipe. **Alloy 602 CA is not aged for service.** Strength comes from solid solution and from primary carbides, not from a gamma prime ageing treatment, and the standard delivery condition is solution annealed. Where a supplier's literature lists solution plus ageing for this grade, it has been carried over from a precipitation-hardening alloy by mistake. ### Welding Weldable by GTAW, GMAW, plasma and SMAW with matching filler: bare wire FM 602 (W.-Nr. 2.4649, AWS A5.14 ERNiCrFe-12) or coated electrodes to AWS A5.11 ENiCrFe-12. Preheat is normally not needed. Root protection with high-purity argon matters, and heat tint should come off with a stainless brush while the weld is still warm. --- ## Forged product forms and size range | Form | Size range | Notes | |---|---|---| | Seamless rolled rings | OD 200 - 3000 mm | Wall 30-500 mm, height to 800 mm | | Forged flanges | OD 100 - 2500 mm | WN, SO, blind, custom drilling | | Discs and blanks | OD 100 - 2000 mm | Solid or trepanned | | Round bar | Ø 60 - 800 mm | Length to 6000 mm | | Shafts and spindles | Ø 80 - 700 mm | Length to 5000 mm, stepped or plain | | Sleeves and bushings | OD 100 - 1500 mm | Bored and trepanned | | Tube sheets | OD to 2500 mm | Undrilled or drilled to drawing | | Single-piece weight | 5 - 8000 kg | Heavier by agreement | We also forge nozzles, valve bodies and seat rings, valve stems, forged blocks, hollow bars, crankshafts and gear blanks in this grade. Sizes outside the table are often still possible. Send the drawing and we will confirm. --- ## Testing and certification - **Melting route.** Material is procured to EAF plus AOD or VOD, with ESR remelting where the specification or the application calls for it. - **Chemical analysis.** Per heat, reported on the certificate against ASTM B166 and B564 limits. - **Mechanical testing.** Room-temperature tensile to ASTM A370 or EN ISO 6892-1. Elevated-temperature and impact testing on request. - **Grain size.** ASTM E112, reported where creep properties are required. - **Ultrasonic testing.** EN 10228-3, SEP 1921 or ASTM A388. State the class and acceptance level at enquiry. - **Surface NDT.** Liquid penetrant to ASTM E165 or EN ISO 3452. - **Certification.** EN 10204 3.1 as standard. EN 10204 3.2 with third-party witness by TÜV, SGS, BV, LR or DNV on request. - **Traceability.** Heat number and part identification hard-stamped or vibro-etched as agreed. --- ## Where Alloy 602 CA forgings are used Buyers come to this grade when a part has to survive above roughly 1000 °C, or when carburisation and metal dusting are eating stainless steels and lower nickel alloys. Typical forged applications: - **Petrochemical and hydrogen.** Steam reformer internals, catalyst support grids, outlet manifold components, and flanges and tube sheets for methanol and ammonia synthesis, where metal dusting sets the service life. - **Industrial furnaces.** Kiln rollers, furnace rolls, radiant tube components, muffles, retorts, roller shafts, and heat-treatment fixtures and baskets running under cyclic heating. - **Waste and energy.** Waste incineration components, glass-melting equipment, and vessels used for vitrifying radioactive waste. - **Pressure equipment.** Forged flanges, tube sheets, nozzles and rolled rings for high-temperature vessels and shell-and-tube exchangers built to ASME Section VIII Div. 1 under Code Case 2359. - **Rotating and valve parts.** Shafts, spindles, sleeves, bushings, valve bodies and seat rings in hot-gas service. --- ## Frequently asked questions ### What is Alloy 602 CA? Alloy 602 CA is a high-carbon nickel-chromium-iron alloy containing 24-26 % chromium, 8-11 % iron and 1.8-2.4 % aluminium, with small additions of yttrium, zirconium and titanium. The aluminium and yttrium build a tightly adherent alumina-chromia scale, which is what gives the alloy an oxidation limit in air of 1200 °C. It is designated UNS N06025 and W.-Nr. 2.4633. ### Is Alloy 602 CA the same as Inconel 602 CA and Nicrofer 6025 HT? Yes. They are the same alloy under different trade names. UNS N06025 is sold as INCONEL alloy 602 CA by Special Metals, as Nicrofer 6025 HT or VDM Alloy 602 CA by VDM Metals, and as RA 602 CA by Rolled Alloys. All of them correspond to W.-Nr. 2.4633 and to the DIN designation NiCr25FeAlY. Those trade names belong to their owners and are listed here for identification only. ### What is the maximum service temperature of Alloy 602 CA? In air the alloy resists oxidation to about 1200 °C (2192 °F), including under cyclic heating. Code limits for pressure equipment are lower: 899 °C (1650 °F) for ASME Section I steam service and 982 °C (1800 °F) for ASME Section VIII Division 1, both under ASME Code Case 2359, and 1150 °C under VdTÜV Werkstoffblatt 540. ### Which standards cover Alloy 602 CA forgings? Forgings are ordered to ASTM B564 or ASME SB-564. Round bar and rod fall under ASTM B166 / ASME SB-166, plate and sheet under ASTM B168 / ASME SB-168, and seamless pipe and tube under ASTM B167 / ASME SB-167. The German designations are DIN 17742, 17750 and 17752, with VdTÜV Werkstoffblatt 540. ### In what condition are Alloy 602 CA forgings supplied? Solution annealed. Alloy 602 CA is strengthened by solid solution and by primary carbides, not by precipitation hardening, so it is not aged for service. After forging, parts are solution annealed at about 1180-1220 °C and cooled quickly. A grain size of at least 70 µm is needed to reach the published creep-rupture values. ### Does Alloy 602 CA contain cobalt? No. Alloy 602 CA is a nickel-chromium-iron alloy. Cobalt is not an alloying element in UNS N06025 and normally appears only as a trace residual. Any description of 602 CA as a nickel-cobalt alloy is wrong. ### Can Alloy 602 CA be welded? Yes, by GTAW, GMAW, plasma or SMAW with matching filler: bare wire FM 602 (W.-Nr. 2.4649, AWS A5.14 ERNiCrFe-12) or coated electrodes to AWS A5.11 ENiCrFe-12. Preheat is normally not needed. If the welded part will run between about 600 °C and 750 °C, a stabilising or post-weld heat treatment is advisable, because rupture ductility drops in roughly the 649-760 °C range. ### Who manufactures Alloy 602 CA forgings in China? Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China. We forge Alloy 602 CA (UNS N06025) into seamless rolled rings, flanges, round bars, discs, shafts, sleeves, bushings and tube sheets to ASTM B564. Enquiries go to sales@steelforgepieces.com or +86-189-2135-9659. ### What testing and certification is supplied with Alloy 602 CA forgings? The standard scope is chemical analysis, room-temperature tensile testing to ASTM A370 or EN ISO 6892-1, grain size to ASTM E112, and ultrasonic testing to EN 10228-3, SEP 1921 or ASTM A388 at the class agreed on order. Certificates are issued to EN 10204 3.1, or to EN 10204 3.2 with third-party witness by TÜV, SGS, BV, LR or DNV on request. ### How do I request a quotation for Alloy 602 CA forgings? Send a drawing or the rough-machined dimensions, the quantity, the specification you are ordering to, the certificate level and the NDT class to sales@steelforgepieces.com. If there is no drawing, the outside diameter, inside diameter, height or length and the condition you need are enough for a budget price. --- ## About the manufacturer Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China, in the Yangtze delta forging cluster about 150 km from Shanghai port. We forge rings, flanges, bars, discs, shafts, sleeves, bushings and tube sheets in carbon steel, alloy steel, tool steel, stainless steel and nickel-based alloys, working to customer drawings and to ASTM, ASME, EN and DIN specifications. Nickel alloys are a regular part of that work. Alongside Alloy 602 CA we forge Inconel 600, 601, 625, 690, 718 and X-750, Incoloy 800H, 800HT and 825, Monel 400 and K-500, Hastelloy C-276, C-22 and B-2, Nimonic 80A, 90 and 263, and Waspaloy. For an Alloy 602 CA enquiry, send a drawing to sales@steelforgepieces.com. If you want to see the paperwork before ordering, we can send a sample EN 10204 3.1 certificate from an earlier 602 CA heat. --- ## Contact **Jiangyin Jiangnan Metal Co., Ltd.** Open-die forging factory - Address: No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China - Telephone: +86-189-2135-9659 - Email: sales@steelforgepieces.com - Web: https://www.steelforgepieces.com/ --- ## Related nickel alloy grades - [Inconel 601](https://www.steelforgepieces.com/Nickel-Alloy/Inconel-601.html) - [Inconel 600](https://www.steelforgepieces.com/Nickel-Alloy/Inconel-600.html) - [Inconel 625](https://www.steelforgepieces.com/Nickel-Alloy/Inconel-625.html) - [Inconel 690](https://www.steelforgepieces.com/Nickel-Alloy/Inconel-690.html) - [Inconel 718](https://www.steelforgepieces.com/Nickel-Alloy/Inconel-718.html) - [Incoloy 800H](https://www.steelforgepieces.com/Nickel-Alloy/Incoloy-800H.html) - [Incoloy 800HT](https://www.steelforgepieces.com/Nickel-Alloy/Incoloy-800HT.html) - [Haynes 230](https://www.steelforgepieces.com/Nickel-Alloy/Haynes-230.html) - [Hastelloy X](https://www.steelforgepieces.com/Nickel-Alloy/Hastelloy-X.html) - [Nimonic 263](https://www.steelforgepieces.com/Nickel-Alloy/Nimonic-263.html) - [Waspaloy](https://www.steelforgepieces.com/Nickel-Alloy/Waspaloy.html) - [All nickel alloys](https://www.steelforgepieces.com/Nickel-Alloy/) On grade selection: Alloy 601 and Incoloy 800HT are the usual step down on cost, but neither matches 602 CA on carburisation resistance or on creep strength above 1000 °C. Haynes 230 competes on high-temperature strength but it is a Ni-Cr-W-Mo alloy with a different corrosion profile. Tell us the service temperature and the atmosphere and we will say whether a cheaper grade will do. --- Published by Jiangyin Jiangnan Metal Co., Ltd. Last reviewed 13 August 2026. Technical data compiled from ASTM B166 and B564, ASME Code Case 2359 and VdTÜV Werkstoffblatt 540, given for information only. It is not a guarantee of properties. Delivered properties are those stated on the mill certificate for the supplied heat. Nicrofer, INCONEL, RA, Hastelloy, Haynes, Incoloy, Monel, Nimonic and Waspaloy are trade names of their respective owners, used here for identification only.