Steel G15CrMoV6-9 +QT2
Heat-treated state
EN 1.7710
+QT2 = quenched and tempered, higher strength class
Choose when higher room-temperature proof strength is needed for wall-thickness reduction in valve/turbine castings, accepting lower ductility, lower impact energy and a slightly reduced upper service temperature.
Values for the +QT2 condition
Other G15CrMoV6-9 tempers and conditions
G15CrMoV6-9 is listed in 3 conditions; see the grade overview at G15CrMoV6-9.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Not a pressure-service supply condition — foundry/shop condition used to ease rough machining and weld repair before final quench and temper. | 340 | 560 | 22 | 165 HB | 8 % IACS |
+QT1Default Quenched and tempered, lower strength class | Standard supply condition for creep-loaded pressure castings: best ductility, toughness and long-term microstructural stability up to ~550 °C. | 480 | 650 | 17 | 15 HRC | — |
+QT2This page Quenched and tempered, higher strength class | Choose when higher room-temperature proof strength is needed for wall-thickness reduction in valve/turbine castings, accepting lower ductility, lower impact energy and a slightly reduced upper service temperature. | 580 | 760 | 14 | 23 HRC | — |
What is G15CrMoV6-9 +QT2?
G15CrMoV6-9 +QT2 is G15CrMoV6-9 heat treated to +QT2 — choose when higher room-temperature proof strength is needed for wall-thickness reduction in valve/turbine castings, accepting lower ductility, lower impact energy and a slightly reduced upper service temperature. G15CrMoV6-9 +QT2 has a yield strength of 580 MPa (84.1 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 75% of steel grades. Elongation at break is 14% and the elastic modulus is 210 GPa (30.5 Msi). G15CrMoV6-9 +QT2 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F). +QT1 is the default condition FabDigit quotes; +QT2 is available on request or by drawing note.
Advantages
- High service temperature — 540°C (1,004 °F), better than 93% of steel grades
- High strength — 580 MPa (84.1 ksi), better than 75% of steel grades
Limitations
- Limited formability — 10/100, worse than 95% of steel grades
- Difficult to machine — 38/100, worse than 80% of steel grades
- Limited ductility — 14%, worse than 75% of steel grades
G15CrMoV6-9 +QT2 properties
Typical room-temperature values for G15CrMoV6-9 +QT2; 18 are specific to this condition. Other listed values are G15CrMoV6-9 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
G15CrMoV6-9 +QT2 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical16
G15CrMoV6-9 +QT2 has a yield strength of 580 MPa (84.1 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 75% of steel grades. Elongation at break is 14% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
G15CrMoV6-9 +QT2 is rated for continuous service to 540°C (1,004 °F). It conducts heat at 40 W/m·K (23.1 BTU/hr·ft·°F), worse than 64% of steel grades. Thermal expansion is 12.3 µm/m·K (6.83 µin/in·°F).
Electrical3
G15CrMoV6-9 +QT2 conducts electricity at 7.5 % IACS, worse than 67% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (15/100), better than 75% of steel grades.
Sustainability4
Producing a kilogram of G15CrMoV6-9 +QT2 takes about 24 MJ of energy and emits 2 kg of CO₂ — less than 97% of steel grades. Typical recycled content is 60%.
Manufacturability8
G15CrMoV6-9 +QT2's machinability is fair (38/100, worse than 80% of steel grades); weldability fair (45/100); formability not recommended (10/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with G15CrMoV6-9 +QT2
Is G15CrMoV6-9 easy to machine?
Machine in the +QT or annealed condition with rigid setups and coated carbide (~80-140 m/min turning); the vanadium carbides are abrasive, so keep feeds positive and avoid dwelling to prevent work hardening.
Can G15CrMoV6-9 be welded?
Weldable with matching 1.5Cr-1Mo-V (or 2.25Cr-1Mo) filler using preheat 200-300 °C, tight interpass control, and mandatory PWHT ~700-740 °C; hydrogen control and low-sulphur base metal are essential to avoid reheat cracking.
Can G15CrMoV6-9 be formed, bent or molded?
Supplied as sand/resin-sand castings — design generous fillets and directional feeding, and always normalize+quench+temper the whole casting rather than cold working it.
What surface finishes work on G15CrMoV6-9?
Shot-blast and prime or use high-temperature aluminium/silicone paint; on steam surfaces rely on the protective oxide plus a corrosion allowance, and use phosphating or nickel plating only for non-service faces.
G15CrMoV6-9 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 |
|---|---|---|
| Cgrade designation number 15 = 0.15 % C | 0.12 – 0.18 | 0.15 |
| Si | ≤ 0.6 | 0.35 |
| Mn | 0.4 – 0.8 | 0.6 |
| Pcreep-steel cleanliness limit | ≤ 0.02 | — |
| S | ≤ 0.02 | — |
| Crdesignation digit 6 → ~1.5 % | 1.3 – 1.7 | 1.5 |
| Modesignation digit 9 → ~0.9 % | 0.8 – 1 | 0.9 |
| Vcarbide former giving creep strength | 0.2 – 0.35 | 0.28 |
| Niresidual | ≤ 0.4 | — |
| Fe | balance | — |
G15CrMoV6-9 +QT2 — frequently asked
What is G15CrMoV6-9 +QT2 used for?
G15CrMoV6-9 +QT2 is typically used for steam turbine valve bodies, high-temperature pump casings, power plant pressure part castings and steam chest housings. In short: creep-resistant cast steel; 550 °C pressure castings; needs preheat and PWHT.
What is the yield strength of G15CrMoV6-9 +QT2?
G15CrMoV6-9 +QT2 has a typical yield strength of 580 MPa (84.1 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 75% of steel grades. Strength varies by condition: see the 3 listed tempers.
Is G15CrMoV6-9 +QT2 easy to machine?
Not especially — machinability is rated fair (38/100, worse than 80% of steel grades). Machine in the +QT or annealed condition with rigid setups and coated carbide (~80-140 m/min turning); the vanadium carbides are abrasive, so keep feeds positive and avoid dwelling to prevent work hardening.
Can G15CrMoV6-9 +QT2 be welded?
With care — weldability is rated fair (45/100). Weldable with matching 1.5Cr-1Mo-V (or 2.25Cr-1Mo) filler using preheat 200-300 °C, tight interpass control, and mandatory PWHT ~700-740 °C; hydrogen control and low-sulphur base metal are essential to avoid reheat cracking.
What surface finishes work on G15CrMoV6-9 +QT2?
Shot-blast and prime or use high-temperature aluminium/silicone paint; on steam surfaces rely on the protective oxide plus a corrosion allowance, and use phosphating or nickel plating only for non-service faces.
Can G15CrMoV6-9 +QT2 be formed, bent or molded?
Supplied as sand/resin-sand castings — design generous fillets and directional feeding, and always normalize+quench+temper the whole casting rather than cold working it.
What is the maximum service temperature of G15CrMoV6-9 +QT2?
G15CrMoV6-9 +QT2 is rated for continuous use to about 540°C (1,004 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- EN 10213 — Steel castings for pressure purposes — CEN (2016)
- DIN 17245 — Ferritic steel castings for elevated temperature service (superseded) — DIN (1987)
- EN 10027-2 — Numerical designation system for steels (material number 1.7710) — CEN (2015)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.13A/13C — Corrosion — ASM International (2003)
- Steel Castings Handbook — Steel Founders' Society of America / ASM (1995)
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.