X20CrMoV11-1
EN 10302 · 1.4922
X20CrMoV11-1 is a pressure-vessel steel (Creep Resistant family) to EN 10302 (1.4922). It has a specified 0.2 % proof stress of 550 MPa and a typical tensile strength of about 750 MPa, with a uniform elongation of 17 %. Nominal carbon content is around 0.17 %. For nonlinear FEA, a bilinear model uses E = 210 GPa up to yield and a tangent modulus of 1209 MPa above it. It is a general-purpose wrought steel selected on strength, cost and availability.
Bilinear material model — nonlinear FEA
Uniform elongation εu = 17.0% · conservative analysis limit ½εu = 8.5%
Bilinear (BISO) approximation. Elastic modulus E up to the 0.2% proof stress R_p0.2, then a single tangent slope Eₜ to the ultimate tensile strength: Eₜ = (Rₘ − R_p0.2) / (εu − R_p0.2/E − 0.002), where εu is the uniform elongation and Rₘ is a typical (nominal) UTS within the specified band. The half-εu figure is a conservative strain limit for the analysis. Treat these as guidance for first-pass models; for critical work use a measured true stress–strain curve for the actual product and condition.
Ratings — engineering judgement
Weldabilitygood
Low carbon (~0.17%) gives good weldability by all common processes; preheat rarely needed in thin sections.
Machinabilitymoderate
Soft and gummy at low carbon — sharp tooling helps surface finish.
Corrosion resistancepoor
No inherent corrosion resistance — protect by paint, galvanising or plating in exposed use.
Hardenabilitylow
Limited hardenability at low carbon — surface hardening is possible but through-hardening is not.
Toughnessmoderate
Adequate toughness for general use at ambient temperature.
Indicative ratings derived from composition and family — engineering guidance, not specification values.
Physical properties
| Density | 7850 | kg/m³ |
| Elastic modulus | 210 | GPa |
| Shear modulus | 80.8 | GPa |
| Poisson's ratio | 0.30 | |
| Thermal expansion | 12.0 | ×10⁻⁶/°C |
| Thermal conductivity | 48 | W/(m·K) |
| Specific heat | 470 | J/(kg·K) |
| Magnetic | Yes |
Typical values for creep resistant steel — use the mill certificate for the specific product.
Chemical composition (wt %)
Typical composition per EN 10302 — confirm exact limits against the standard.
Available forms
Common applications
- Boilers and pressure vessels
- Storage tanks and process drums
- Heat exchanger shells
- Piping components (to code)
History
The chromium-molybdenum (and later high-chromium) creep-resisting steels were developed for power-station boilers and refinery reactors that run red-hot for decades — chromium for oxidation and hydrogen resistance, molybdenum (and vanadium/niobium) for creep strength. EN 10028-2/EN 10302 and ASTM A335/A213 carry the family. A creep-resisting grade — the chromium and molybdenum (and V/Nb) keep strength at temperature where plain C-Mn plate would creep.
- 1930Cr–Mo steels adopted for high-temperature boiler and refinery service
- 19702¼Cr–1Mo (10CrMo9-10 / P22) becomes the refinery workhorse
- 1985Modified 9Cr–1Mo (Grade 91) enables higher-efficiency supercritical plant
This profile is generated from the grade's core data and family. Composition is decoded from the designation where its naming system defines it; physical properties are family-typical and ratings are indicative. Confirm critical values against the governing standard or the mill certificate. Equivalents, historical designations and hand-written expert notes are added per grade over time.