1.4935 (X20CrMoWV12-1) Creep-Resisting Steel Forgings: AISI 422, UNS S42200, SUH616
1.4935 is the EN material number for X20CrMoWV12-1, a martensitic creep-resisting chromium steel listed in EN 10302, the European standard covering creep resisting steels, nickel and cobalt alloys in bar, rod and flat products. The grade runs 11.0 to 12.5 % chromium with deliberate additions of molybdenum, tungsten and vanadium. Those three elements form carbides that resist coarsening at temperature, which is where the creep strength comes from. Its nearest counterparts abroad are AISI 422 and AISI 616 (UNS S42200) in the USA and SUH616 in Japan, though the tungsten, carbon and nickel ranges of those grades differ from EN 1.4935.
Continuous service is normally taken to about 580 °C for creep and 600 °C for scaling. The steel is supplied quenched and tempered as +QT700 (Rm 700 to 850 MPa) or +QT800 (Rm 800 to 950 MPa). Typical work is steam and gas turbine blades, valve spindles and stems, rotor parts and bolting that has to hold load hot.
Jiangyin Jiangnan Metal Co., Ltd. forges 1.4935 to customer drawing: round, square and flat bars, turbine blade blanks, hollow bars and sleeves, seamless rolled rings, blocks and discs, valve spindles and double-end studs. Drawings to sales@steelforgepieces.com or +86-189-2135-9659.
Identification and basic data
| EN material number | 1.4935 |
|---|---|
| EN steel name | X20CrMoWV12-1 |
| Standard | EN 10302:2008, creep resisting steels, nickel and cobalt alloys |
| Class | Martensitic creep-resisting (heat-resisting) alloy steel |
| Melting route available | ESR remelted material available on request |
| Density | 7.7 g/cm3 |
| Young's modulus | 216 GPa |
| Thermal conductivity | 24 W/(m·K) |
| Specific heat capacity | 460 J/(kg·K) |
| Linear expansion coefficient | 10.5 to 12.5 × 10-6 m/(m·K) |
| Delivery conditions | +QT700, +QT800 |
| Weldability | Difficult. Welding group 7.2 of ISO/TR 20172 |
| Main uses | Turbine blades, valve spindles and stems, rotor parts, high-temperature fasteners |
Physical values are indicative figures for the grade. Certified values for a given heat appear on the EN 10204 3.1 certificate issued with the goods.
Chemical composition
| C | Si | Mn | P | S | Cr | Mo | Ni | V | W |
|---|---|---|---|---|---|---|---|---|---|
| 0.17–0.24 | 0.10–0.50 | 0.30–0.80 | 0.025 | 0.015 | 11.0–12.5 | 0.80–1.20 | 0.30–0.80 | 0.20–0.35 | 0.40–0.60 |
Some supplier datasheets publish the vanadium range as 0.25 to 0.35 %. Where the narrower range matters for your application, state it on the order and it will be met and certified.
Mechanical properties at room temperature
| Property | +QT700 | +QT800 |
|---|---|---|
| Tensile strength Rm, MPa | 700–850 | 800–950 |
| Proof strength Rp0.2, MPa | 500 min | 600 min |
| Elongation A, % | 15 min | 14 min |
Minimum elongation varies with product form, ruling section and specimen direction, and transverse values sit below longitudinal. Confirm the row of EN 10302 that applies to your product form at enquiry.
High-temperature and creep data
| Test temperature, °C | +QT700 | +QT800 |
|---|---|---|
| 50 | 465 | 585 |
| 100 | 460 | 560 |
| 150 | 445 | 545 |
| 200 | 430 | 530 |
| 250 | 415 | 505 |
| 300 | 390 | 480 |
| 350 | 380 | 450 |
| 400 | 360 | 420 |
| 450 | 330 | 380 |
| 500 | 290 | 335 |
| 550 | 250 | 280 |
Creep-rupture strength is quoted as 275 MPa minimum for 100,000 h at 500 °C. For design work, take the creep-rupture and 1 % creep-limit tables of EN 10302 against your own stress and design life. The 580 °C figure often seen for this grade is a general service guide, not a design allowable.
Heat treatment
| Austenitising and quenching | 1020 to 1070 °C |
|---|---|
| Tempering | 680 to 780 °C |
| Resulting class | +QT700 from the upper tempering range, +QT800 from the lower |
Forging is followed by a full quench and temper cycle to bring up tempered martensite. Ruling section, quench medium and tempering temperature together decide the class that can be certified, so heavy sections are worth reviewing for through-hardening before +QT800 is fixed on the drawing.
Equivalent grades
| Standard or origin | Designation |
|---|---|
| EN 10302, Europe | 1.4935, X20CrMoWV12-1 |
| AISI / UNS, USA | AISI 422, AISI 616, Alloy 616, Grade 616, UNS S42200 |
| JIS G 4311, Japan | SUH616 |
| UNI 7500, Italy | X22CrMoWV12-1 |
| Older and works designations | EW 4935, HWMoV3 |
Near-equivalent is not the same as identical
| Grade | C | Cr | Mo | Ni | V | W |
|---|---|---|---|---|---|---|
| EN 1.4935, X20CrMoWV12-1 | 0.17–0.24 | 11.0–12.5 | 0.80–1.20 | 0.30–0.80 | 0.20–0.35 | 0.40–0.60 |
| JIS SUH616 | 0.20–0.25 | 11.0–13.0 | 0.75–1.25 | 0.50–1.00 | 0.20–0.30 | 0.75–1.25 |
| AISI 422, UNS S42200 | 0.20–0.25 | 11.0–12.5 | 0.75–1.25 | 0.50–1.00 | 0.15–0.30 | 0.75–1.25 |
Tungsten is the clearest difference. EN 1.4935 caps it at 0.60 %, while SUH616 and AISI 422 both run up to 1.25 %. Carbon and nickel also sit higher in the Japanese and American grades. Use these as selection equivalents, and name one ordering standard on the drawing rather than assuming free substitution between them.
1.4935 and 1.4923 are different grades
1.4923 is X22CrMoV12-1 and carries no deliberate tungsten. 1.4935 is X20CrMoWV12-1 with 0.40 to 0.60 % tungsten, which is what lifts its creep strength. Both are 12 % chromium martensitic grades in EN 10302 with adjacent numbers, and enquiries arrive with the two transposed often enough that it is worth checking. Send the drawing and the grade will be confirmed before quoting.
Forged product forms
Everything below is open-die forged to order in 1.4935, rough or finish machined to drawing, supplied quenched and tempered with an EN 10204 3.1 certificate.
| Family | Items |
|---|---|
| Bars | Round bars and rods, square bars, rectangular and flat bars, turbine blade blanks |
| Hollow sections | Hollow bars, sleeves, bushes and bushings, forged pipes and tubes, barrels, casings, shells, cylinders, hubs, housings |
| Rings | Forged rings, seamless rolled rings |
| Solid sections | Blocks, discs, plates |
| Turbine parts | Steam and gas turbine valve spindles, stems and rods |
| Fasteners | Double-headed and double-end studs, bolts, high-temperature fasteners |
Other 1.4935 forgings are made to requirement. For a quotation, send the drawing or a dimensional sketch with the delivery class (+QT700 or +QT800), quantity and test scope.
Common questions
What is steel 1.4935?
The EN material number for X20CrMoWV12-1, a martensitic creep-resisting chromium steel in EN 10302. It holds 11.0 to 12.5 % chromium with 0.80 to 1.20 % molybdenum, 0.40 to 0.60 % tungsten and 0.20 to 0.35 % vanadium, and is used mainly for turbine blades, valve spindles and hot bolting.
What is 1.4935 equivalent to?
AISI 422 and AISI 616 (UNS S42200) in the USA, SUH616 in Japan, X22CrMoWV12-1 to UNI 7500 in Italy. These are near-equivalents rather than identical grades. The composition comparison above sets out where they part company.
What is the maximum service temperature of 1.4935?
About 580 °C for creep resistance and about 600 °C for scaling resistance in continuous service. Figures up to 650 °C appear in some supplier literature. Fix the design temperature from the EN 10302 creep-rupture data for your actual stress and service life.
Is 1.4935 a stainless steel?
On the border. At 11.0 to 12.5 % chromium it can meet the EN 10088-1 definition, but EN 10302 specifies it for hot strength and oxidation resistance rather than corrosion resistance. Martensitic creep-resisting steel is the accurate description, and it should not be selected as a corrosion-resisting grade.
Can 1.4935 be welded?
Not easily. It falls in welding group 7.2 of ISO/TR 20172 and needs preheat, interpass control and post-weld heat treatment. Designing the part as a single forging removes the joint, which is a common reason for specifying forgings in this grade.
Which delivery class should be ordered?
+QT700 where ductility and toughness carry more weight, at Rm 700 to 850 MPa and A 15 % minimum. +QT800 where strength is needed, at 800 to 950 MPa and A 14 % minimum. Heavy sections should be checked for through-hardening before +QT800 is specified.
Ordering
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging works at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China. We forge carbon, alloy, tool and stainless steels and nickel-base alloys, including EN 10302 creep-resisting grades such as 1.4935, and supply turbine, power generation, petrochemical and pressure equipment builders in China and abroad.
Pricing depends on the drawing, piece weight, delivery class and test scope, so each enquiry is quoted individually. Send the drawing, quantity, delivery class and test requirements to sales@steelforgepieces.com or call +86-189-2135-9659. Quotations normally go out within one working day.
Data sources and revision
Composition and mechanical data on this page is compiled from EN 10302:2008 for grade 1.4935, JIS G 4311 for SUH616, UNI 7500 for X22CrMoWV12-1, and ISO/TR 20172 for the welding group. Where published sources disagree on maximum service temperature, the lower figure is quoted here. Published by Jiangyin Jiangnan Metal Co., Ltd., revised 27 September 2026. A plain-text version of this sheet is at 1.4935.md.
This sheet is for guidance in enquiry and selection. It does not replace the governing standard or the material certificate, and responsibility for grade choice and design verification stays with the purchaser.
Related grades and forms
Other creep-resisting and high-temperature grades: 1.4923 X22CrMoV12-1, 1.4922 X20CrMoV11-1, 17-4PH, PH13-8Mo, 17-7PH. Nickel-base alloys for higher temperature: Inconel X-750, Inconel 617, Incoloy 800H. By form: forged rings, forged shafts, forged pipes.