Steel 10CrMo9-10 +A (Annealed)
Heat-treated state
EN 10CrMo9-10 · ASTM A335 P22
Softest condition, supplied for heavy machining, deep forming or forging stock before final +NT/+QT treatment.
Values for the +A condition
Other 10CrMo9-10 tempers and conditions
10CrMo9-10 is listed in 3 conditions; see the grade overview at 10CrMo9-10.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
+AThis page Annealed | Softest condition, supplied for heavy machining, deep forming or forging stock before final +NT/+QT treatment. | 280 | 470 | 28 | 145 HB | — |
+NTDefault Normalized and tempered | The standard delivery condition for boiler tube, header and pressure-vessel plate; balanced creep strength, toughness and weldability. | 360 | 545 | 24 | 165 HB | — |
Quenched and tempered | Chosen for thick-wall vessels, forgings and hydroprocessing reactor sections needing higher room-temperature strength and through-thickness toughness. | 460 | 650 | 20 | 19 HRC | — |
What is 10CrMo9-10 +A?
10CrMo9-10 +A is 10CrMo9-10 heat treated to +A — softest condition, supplied for heavy machining, deep forming or forging stock before final +NT/+QT treatment. 10CrMo9-10 +A has a yield strength of 280 MPa (40.6 ksi) and a tensile strength of 470 MPa (68.2 ksi) — weaker than 90% of steel grades. Elongation at break is 28% and the elastic modulus is 210 GPa (30.5 Msi). 10CrMo9-10 +A has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,450°C (2,642 °F). +NT is the default condition FabDigit quotes; +A is available on request or by drawing note.
Advantages
- Tough — resists crack growth — 150 MPa·√m (136.5 ksi·√in), better than 96% of steel grades
- High service temperature — 550°C (1,022 °F), better than 95% of steel grades
- Ductile — tolerates forming and impact — 28%, better than 89% of steel grades
- Easy to machine — 62/100, better than 89% of steel grades
- Forms and bends easily — 65/100, better than 81% of steel grades
Limitations
- Low strength — 280 MPa (40.6 ksi), worse than 90% of steel grades
10CrMo9-10 +A properties
Typical room-temperature values for 10CrMo9-10 +A; 12 are specific to this condition. Other listed values are 10CrMo9-10 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
10CrMo9-10 +A has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,450°C (2,642 °F).
Mechanical16
10CrMo9-10 +A has a yield strength of 280 MPa (40.6 ksi) and a tensile strength of 470 MPa (68.2 ksi) — weaker than 90% of steel grades. Elongation at break is 28% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
10CrMo9-10 +A is rated for continuous service to 550°C (1,022 °F). It conducts heat at 37 W/m·K (21.4 BTU/hr·ft·°F), worse than 71% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
10CrMo9-10 +A conducts electricity at 8 % IACS, better than 55% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (15/100), better than 75% of steel grades.
Sustainability4
Producing a kilogram of 10CrMo9-10 +A takes about 31 MJ of energy and emits 2.3 kg of CO₂ — more than 64% of steel grades. Typical recycled content is 25%.
Manufacturability7
10CrMo9-10 +A's machinability is good (62/100, better than 89% of steel grades); weldability good (60/100); formability good (65/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 10CrMo9-10 +A
Is 10CrMo9-10 easy to machine?
Machines like 4130/4140 at ~55 % of 1212; use rigid setups, coated carbide, moderate speeds and generous coolant — bainitic +QT material work-hardens and loads tools faster.
Can 10CrMo9-10 be welded?
P-No.5A: preheat 200–250 °C, maintain interpass, use matching 2.25Cr-1Mo consumables (E9018-B3 / ER90S-B3) and mandatory PWHT at 690–750 °C to restore toughness and avoid hydrogen cracking.
Can 10CrMo9-10 be formed, bent or molded?
Hot bending/forging at 1050–1150 °C followed by re-normalizing and tempering is preferred; cold bending is possible on tube with generous radii but needs stress-relief afterwards.
What surface finishes work on 10CrMo9-10?
No anodizing; protect with high-temperature aluminium-silicone paint, phosphate or metallizing, and control corrosion under insulation in cyclic service.
10CrMo9-10 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| C | 0.08 – 0.14 | 0.11 |
| Si | ≤ 0.5 | 0.25 |
| Mn | 0.4 – 0.8 | 0.55 |
| Plower P specified for temper-embrittlement-resistant (J-factor) grades | ≤ 0.02 | 0.01 |
| S | ≤ 0.01 | 0.01 |
| Cr | 2 – 2.5 | 2.25 |
| Mo | 0.9 – 1.1 | 1 |
| Niresidual | ≤ 0.3 | 0.15 |
| Curesidual | ≤ 0.3 | 0.1 |
| Fe | balance | — |
10CrMo9-10 +A — frequently asked
What is 10CrMo9-10 +A used for?
10CrMo9-10 +A is typically used for boiler tubes, reheater/superheater tubing and refinery piping. In short: most weldable Cr-Mo here; standard boiler tube steel; 570 °C service limit.
What is the yield strength of 10CrMo9-10 +A?
10CrMo9-10 +A has a typical yield strength of 280 MPa (40.6 ksi) and a tensile strength of 470 MPa (68.2 ksi) — weaker than 90% of steel grades. Strength varies by condition: see the 3 listed tempers.
Is 10CrMo9-10 +A easy to machine?
Reasonably — machinability is rated good (62/100, better than 89% of steel grades). Machines like 4130/4140 at ~55 % of 1212; use rigid setups, coated carbide, moderate speeds and generous coolant — bainitic +QT material work-hardens and loads tools faster.
Can 10CrMo9-10 +A be welded?
Yes — weldability is rated good (60/100). P-No.5A: preheat 200–250 °C, maintain interpass, use matching 2.25Cr-1Mo consumables (E9018-B3 / ER90S-B3) and mandatory PWHT at 690–750 °C to restore toughness and avoid hydrogen cracking.
What surface finishes work on 10CrMo9-10 +A?
No anodizing; protect with high-temperature aluminium-silicone paint, phosphate or metallizing, and control corrosion under insulation in cyclic service.
Can 10CrMo9-10 +A be formed, bent or molded?
Hot bending/forging at 1050–1150 °C followed by re-normalizing and tempering is preferred; cold bending is possible on tube with generous radii but needs stress-relief afterwards.
What is the maximum service temperature of 10CrMo9-10 +A?
10CrMo9-10 +A is rated for continuous use to about 550°C (1,022 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- EN 10216-2 Seamless steel tubes for pressure purposes — non-alloy and alloy steel tubes with specified elevated temperature properties — CEN (2020)
- EN 10028-2 Flat products made of steels for pressure purposes — Alloy steels with specified elevated temperature properties — CEN (2017)
- ASTM A335/A335M Seamless Ferritic Alloy-Steel Pipe for High-Temperature Service (Grade P22) — ASTM (2023)
- ASTM A387/A387M Pressure Vessel Plates, Alloy Steel, Chromium-Molybdenum (Grade 22) — ASTM (2021)
- ASME BPVC Section II Part D — Material Properties — ASME (2023)
- ASM Handbook Vol. 1: Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- API RP 941 Steels for Hydrogen Service at Elevated Temperatures — API (2016)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.