Steel G17CrMo5-5 +N+T
Heat-treated state
ASTM A217 Gr. WC6 · EN 1.7357
+N+T = normalized (~ 920–960 °C, air cool) and tempered 680–730 °C
Standard route for thick-walled or complex castings where quenching risks cracking; slightly lower yield than +QT but very stable at temperature.
Values for the +N+T condition
Other G17CrMo5-5 tempers and conditions
G17CrMo5-5 is listed in 5 conditions; see the grade overview at G17CrMo5-5.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Choose for maximum machinability and lowest hardness before final quench-and-temper or for low-stress non-pressure parts. | 290 | 500 | 26 | 145 HB | — |
+N+TThis page Normalized (~ 920–960 °C, air cool) and tempered 680–730 °C | Standard route for thick-walled or complex castings where quenching risks cracking; slightly lower yield than +QT but very stable at temperature. | 350 | 545 | 23 | 165 HB | 7.8 % IACS |
Quenched and tempered, then post-weld/stress-relieved 620–680 °C | For castings that have been weld-repaired or welded into assemblies; PWHT below the tempering temperature restores toughness with a small drop in strength. | 360 | 555 | 23 | 168 HB | 7.8 % IACS |
+QTDefault Quenched and tempered | Default delivery condition per EN 10213 for pressure castings: best combination of 315 MPa min yield, 20 % elongation and 40 J CVN. | 380 | 570 | 22 | 175 HB | — |
As fabricated | Foundry intermediate state only — not permitted for pressure service; hard, brittle bainitic/martensitic areas and high residual stress. | 400 | 650 | 12 | 18 HRC | 7.6 % IACS |
What is G17CrMo5-5 +N+T?
G17CrMo5-5 +N+T is G17CrMo5-5 heat treated to +N+T — standard route for thick-walled or complex castings where quenching risks cracking; slightly lower yield than +QT but very stable at temperature. G17CrMo5-5 +N+T has a yield strength of 350 MPa (50.8 ksi) and a tensile strength of 545 MPa (79 ksi) — weaker than 74% of steel grades. Elongation at break is 23% and the elastic modulus is 210 GPa (30.5 Msi). G17CrMo5-5 +N+T 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; +N+T is available on request or by drawing note.
Advantages
- High service temperature — 550°C (1,022 °F), better than 95% of steel grades
Limitations
- Limited formability — 22/100, worse than 76% of steel grades
G17CrMo5-5 +N+T properties
Typical room-temperature values for G17CrMo5-5 +N+T; 22 are specific to this condition. Other listed values are G17CrMo5-5 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
G17CrMo5-5 +N+T 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
G17CrMo5-5 +N+T has a yield strength of 350 MPa (50.8 ksi) and a tensile strength of 545 MPa (79 ksi) — weaker than 74% of steel grades. Elongation at break is 23% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
G17CrMo5-5 +N+T is rated for continuous service to 550°C (1,022 °F). It conducts heat at 42 W/m·K (24.3 BTU/hr·ft·°F), worse than 56% of steel grades. Thermal expansion is 12.3 µm/m·K (6.83 µin/in·°F).
Electrical3
G17CrMo5-5 +N+T conducts electricity at 7.8 % IACS, worse than 57% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (15/100), better than 75% of steel grades.
Sustainability4
Producing a kilogram of G17CrMo5-5 +N+T takes about 27 MJ of energy and emits 2.2 kg of CO₂ — less than 59% of steel grades. Typical recycled content is 80%.
Manufacturability8
G17CrMo5-5 +N+T's machinability is fair (52/100, better than 52% 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 G17CrMo5-5 +N+T
Is G17CrMo5-5 easy to machine?
Machines like annealed 4130/4140 at ~60 % of AISI 1212 — use rigid setups, coated carbide, moderate speed and generous coolant; expect hard spots at chills and in un-tempered as-cast areas.
Can G17CrMo5-5 be welded?
Weldable with matched E/ER 80S-B2 or E8018-B2 filler; preheat 200–250 °C, interpass ≤ 350 °C, low-hydrogen practice, and mandatory PWHT at 680–730 °C to avoid hydrogen and reheat cracking.
Can G17CrMo5-5 be formed, bent or molded?
Sand or investment cast with generous risering (solidification range is wide); design 3–5 % shrink allowance, avoid abrupt section changes, and always heat treat (+N+T or +QT) before proof testing.
What surface finishes work on G17CrMo5-5?
Not corrosion resistant — shot blast then apply high-temperature aluminium/silicone paint, Al metallizing or Ni/Cr plating; machined sealing faces are often hardfaced with Stellite in valve service.
G17CrMo5-5 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 |
|---|---|---|
| CEN 10213; A217 WC6 allows 0.05–0.20 | 0.15 – 0.2 | 0.17 |
| Si | ≤ 0.6 | 0.4 |
| Mn | 0.5 – 1 | 0.75 |
| P | ≤ 0.02 | 0.01 |
| S | ≤ 0.02 | 0.01 |
| Cr | 1 – 1.5 | 1.25 |
| Mo | 0.45 – 0.65 | 0.55 |
| Niresidual | ≤ 0.4 | 0.15 |
| Curesidual | ≤ 0.3 | 0.15 |
| Vresidual | ≤ 0.05 | 0.02 |
| Fe | balance | — |
G17CrMo5-5 +N+T — frequently asked
What is G17CrMo5-5 +N+T used for?
G17CrMo5-5 +N+T is typically used for steam valve bodies, power plant pressure castings and high-temperature piping fittings. In short: A217 WC6 pressure casting; creep service to 550 °C; standard steam valve grade.
What is the yield strength of G17CrMo5-5 +N+T?
G17CrMo5-5 +N+T has a typical yield strength of 350 MPa (50.8 ksi) and a tensile strength of 545 MPa (79 ksi) — weaker than 74% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is G17CrMo5-5 +N+T easy to machine?
Reasonably — machinability is rated fair (52/100, better than 52% of steel grades). Machines like annealed 4130/4140 at ~60 % of AISI 1212 — use rigid setups, coated carbide, moderate speed and generous coolant; expect hard spots at chills and in un-tempered as-cast areas.
Can G17CrMo5-5 +N+T be welded?
Yes — weldability is rated good (57/100). Weldable with matched E/ER 80S-B2 or E8018-B2 filler; preheat 200–250 °C, interpass ≤ 350 °C, low-hydrogen practice, and mandatory PWHT at 680–730 °C to avoid hydrogen and reheat cracking.
What surface finishes work on G17CrMo5-5 +N+T?
Not corrosion resistant — shot blast then apply high-temperature aluminium/silicone paint, Al metallizing or Ni/Cr plating; machined sealing faces are often hardfaced with Stellite in valve service.
Can G17CrMo5-5 +N+T be formed, bent or molded?
Sand or investment cast with generous risering (solidification range is wide); design 3–5 % shrink allowance, avoid abrupt section changes, and always heat treat (+N+T or +QT) before proof testing.
What is the maximum service temperature of G17CrMo5-5 +N+T?
G17CrMo5-5 +N+T 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.
What is the difference between G17CrMo5-5 +QT and G17CrMo5-5-F?
+QT is the default condition — default delivery condition per EN 10213 for pressure castings: best combination of 315 MPa min yield, 20 % elongation and 40 J CVN. F: foundry intermediate state only — not permitted for pressure service; hard, brittle bainitic/martensitic areas and high residual stress. Yield strength is 380 MPa in +QT versus 400 MPa in F.
Sources
- EN 10213 — Steel castings for pressure purposes — CEN (2016)
- ASTM A217/A217M — Martensitic stainless and alloy steel castings for pressure-containing parts (Gr. WC6) — ASTM International (2021)
- ASME BPVC Section II Part D — Material properties (1.25Cr-0.5Mo) — ASME (2023)
- Steel Castings Handbook, 6th ed. — Steel Founders' Society of America / ASM (1995)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- GB/T 16253 — (ZG20CrMo class) — 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.