Steel G17CrMo9-10 +NT (Normalized and tempered)
Heat-treated state
ASTM A217 Gr. WC9 · EN 1.7379
Common route for thick-wall WC9 castings where liquid quenching is impractical; slightly lower yield and toughness than +QT.
Values for the +NT condition
Other G17CrMo9-10 tempers and conditions
G17CrMo9-10 is listed in 3 conditions; see the grade overview at G17CrMo9-10.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Pick when the casting must be heavily machined or repair-welded before the final strengthening heat treatment. | 270 | 480 | 26 | 145 HB | 8 % IACS |
+NTThis page Normalized and tempered | Common route for thick-wall WC9 castings where liquid quenching is impractical; slightly lower yield and toughness than +QT. | 320 | 540 | 24 | 170 HB | 8 % IACS |
+QTDefault Quenched and tempered | Standard EN 10213 supply condition for pressure-retaining Cr-Mo valve and pump castings; best combination of yield strength and toughness. | 340 | 570 | 22 | 180 HB | 8 % IACS |
What is G17CrMo9-10 +NT?
G17CrMo9-10 +NT is G17CrMo9-10 heat treated to +NT — common route for thick-wall WC9 castings where liquid quenching is impractical; slightly lower yield and toughness than +QT. G17CrMo9-10 +NT has a yield strength of 320 MPa (46.4 ksi) and a tensile strength of 540 MPa (78.3 ksi) — weaker than 81% of steel grades. Elongation at break is 24% and the elastic modulus is 210 GPa (30.5 Msi). G17CrMo9-10 +NT 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). +QT is the default condition FabDigit quotes; +NT is available on request or by drawing note.
Advantages
- High service temperature — 550°C (1,022 °F), better than 95% of steel grades
- Good corrosion resistance — 22/100, better than 90% of steel grades
- Tough — resists crack growth — 115 MPa·√m (104.7 ksi·√in), better than 77% of steel grades
Limitations
- Hard to polish — 45/100, worse than 84% of steel grades
- Low strength — 320 MPa (46.4 ksi), worse than 81% of steel grades
- Limited formability — 22/100, worse than 76% of steel grades
G17CrMo9-10 +NT properties
Typical room-temperature values for G17CrMo9-10 +NT; 22 are specific to this condition. Other listed values are G17CrMo9-10 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
G17CrMo9-10 +NT 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
G17CrMo9-10 +NT has a yield strength of 320 MPa (46.4 ksi) and a tensile strength of 540 MPa (78.3 ksi) — weaker than 81% of steel grades. Elongation at break is 24% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
G17CrMo9-10 +NT 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 12.2 µm/m·K (6.78 µin/in·°F).
Electrical3
G17CrMo9-10 +NT conducts electricity at 8 % IACS, better than 55% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (22/100), better than 90% of steel grades.
Sustainability4
Producing a kilogram of G17CrMo9-10 +NT takes about 33 MJ of energy and emits 2.4 kg of CO₂ — more than 76% of steel grades. Typical recycled content is 70%.
Manufacturability7
G17CrMo9-10 +NT's machinability is fair (53/100, better than 53% of steel grades); weldability good (57/100); formability poor (22/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with G17CrMo9-10 +NT
Is G17CrMo9-10 easy to machine?
Machine in the tempered condition with rigid setups, carbide tooling and 60–120 m/min surface speed; remove the abrasive cast skin with a dedicated first pass.
Can G17CrMo9-10 be welded?
Weldable with matching 2.25Cr-1Mo (E9018-B3 / ER90S-B3) consumables using 200–250 °C preheat, controlled interpass and 690–740 °C post-weld heat treatment; avoid hydrogen pickup.
Can G17CrMo9-10 be formed, bent or molded?
Supplied as sand or investment castings — design generous fillets, directional risering and 2–3 % feeding allowance; no cold forming.
What surface finishes work on G17CrMo9-10?
Shot blast and paint or apply weld overlay/cladding for wet service; can be phosphated or hard-chrome plated on seat areas but is not corrosion resistant bare.
G17CrMo9-10 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 |
|---|---|---|
| CASTM A217 WC9 allows 0.05–0.18 | 0.13 – 0.2 | 0.17 |
| Si | ≤ 0.6 | 0.35 |
| MnA217 WC9: 0.40–0.70 | 0.5 – 0.9 | 0.7 |
| P | ≤ 0.02 | 0.01 |
| S | ≤ 0.02 | 0.01 |
| CrA217 WC9: 2.00–2.75 | 2 – 2.5 | 2.25 |
| Mo | 0.9 – 1.2 | 1.05 |
| Niresidual | ≤ 0.3 | 0.15 |
| Fe | balance | — |
G17CrMo9-10 +NT — frequently asked
What is G17CrMo9-10 +NT used for?
G17CrMo9-10 +NT is typically used for high-temperature/high-pressure valve bodies, power plant pressure castings and petrochemical fittings. In short: standard 2.25Cr-1Mo valve casting; WC9 pressure-service grade; weldable creep-resistant casting.
What is the yield strength of G17CrMo9-10 +NT?
G17CrMo9-10 +NT has a typical yield strength of 320 MPa (46.4 ksi) and a tensile strength of 540 MPa (78.3 ksi) — weaker than 81% of steel grades. Strength varies by condition: see the 3 listed tempers.
Is G17CrMo9-10 +NT easy to machine?
Reasonably — machinability is rated fair (53/100, better than 53% of steel grades). Machine in the tempered condition with rigid setups, carbide tooling and 60–120 m/min surface speed; remove the abrasive cast skin with a dedicated first pass.
Can G17CrMo9-10 +NT be welded?
Yes — weldability is rated good (57/100). Weldable with matching 2.25Cr-1Mo (E9018-B3 / ER90S-B3) consumables using 200–250 °C preheat, controlled interpass and 690–740 °C post-weld heat treatment; avoid hydrogen pickup.
What surface finishes work on G17CrMo9-10 +NT?
Shot blast and paint or apply weld overlay/cladding for wet service; can be phosphated or hard-chrome plated on seat areas but is not corrosion resistant bare.
Can G17CrMo9-10 +NT be formed, bent or molded?
Supplied as sand or investment castings — design generous fillets, directional risering and 2–3 % feeding allowance; no cold forming.
What is the maximum service temperature of G17CrMo9-10 +NT?
G17CrMo9-10 +NT 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 10213 — Steel castings for pressure purposes — CEN (2016)
- ASTM A217/A217M — Steel Castings, Martensitic Stainless and Alloy, for Pressure-Containing Parts, Suitable for High-Temperature Service — ASTM (2021)
- ASME BPVC Section II Part D — Material properties (2.25Cr-1Mo) — ASME (2023)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- GB/T 16253 — (ZG15Cr2Mo1) — SAC (2019)
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.