Steel G9Ni14-QT (Quenched and tempered)
Heat-treated state · default condition
EN 1.5638
Standard delivery condition for EN 10213 low-temperature valve and pump castings needing −100 °C toughness with Rp0.2 ≥ 360 MPa.
Values for the QT condition
Other G9Ni14 tempers and conditions
G9Ni14 is listed in 3 conditions; see the grade overview at G9Ni14.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
QT heavy section | Same heat treatment on heavy-wall castings; reduced cooling rate lowers guaranteed yield strength and mid-wall toughness. | 370 | 530 | 24 | 165 HB | 6.2 % IACS |
Double) normalized and tempered | Alternative EN 10213 route for large or complex castings where quenching risks distortion/cracking; slightly lower strength, similar low-temperature toughness. | 385 | 540 | 26 | 168 HB | 6.2 % IACS |
QTDefaultThis page Quenched and tempered | Standard delivery condition for EN 10213 low-temperature valve and pump castings needing −100 °C toughness with Rp0.2 ≥ 360 MPa. | 400 | 560 | 25 | 175 HB | 5.8 % IACS |
What is G9Ni14-QT?
G9Ni14-QT is G9Ni14 heat treated to QT — standard delivery condition for EN 10213 low-temperature valve and pump castings needing −100 °C toughness with Rp0.2 ≥ 360 MPa. G9Ni14-QT has a yield strength of 400 MPa (58 ksi) and a tensile strength of 560 MPa (81.2 ksi) — weaker than 60% of steel grades. Elongation at break is 25% and the elastic modulus is 204 GPa (29.6 Msi). G9Ni14-QT has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,440°C (2,624 °F).
Advantages
- Tough — resists crack growth — 130 MPa·√m (118.3 ksi·√in), better than 89% of steel grades
- Ductile — tolerates forming and impact — 25%, better than 77% of steel grades
Limitations
- Poor heat conductor — 32 W/m·K (18.5 BTU/hr·ft·°F), worse than 82% of steel grades
- Low electrical conductivity — 5.8 % IACS, worse than 79% of steel grades
- Limited service temperature — 300°C (572 °F), worse than 78% of steel grades
G9Ni14-QT properties
Typical room-temperature values for G9Ni14-QT; 22 are specific to this condition. Other listed values are G9Ni14 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
G9Ni14-QT has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,440°C (2,624 °F).
Mechanical16
G9Ni14-QT has a yield strength of 400 MPa (58 ksi) and a tensile strength of 560 MPa (81.2 ksi) — weaker than 60% of steel grades. Elongation at break is 25% and the elastic modulus is 204 GPa (29.6 Msi).
Thermal6
G9Ni14-QT is rated for continuous service to 300°C (572 °F). It conducts heat at 32 W/m·K (18.5 BTU/hr·ft·°F), worse than 82% of steel grades. Thermal expansion is 11.5 µm/m·K (6.39 µin/in·°F).
Electrical3
G9Ni14-QT conducts electricity at 5.8 % IACS, worse than 79% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (15/100), better than 75% of steel grades.
Sustainability4
Producing a kilogram of G9Ni14-QT takes about 31 MJ of energy and emits 2.4 kg of CO₂ — more than 64% of steel grades. Typical recycled content is 75%.
Manufacturability8
G9Ni14-QT's machinability is good (55/100, better than 62% of steel grades); weldability good (65/100); formability poor (25/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with G9Ni14-QT
Is G9Ni14 easy to machine?
Machines like a Q&T low-alloy steel at ~170 HB — sharp carbide inserts, moderate speed, rigid setup; watch for skin scale and casting hard spots.
Can G9Ni14 be welded?
Weldable with low-hydrogen SMAW/GTAW using matching 3.5Ni or Ni-base consumables, preheat 100–150 °C, interpass control and PWHT ~580–620 °C; avoid high heat input to protect −100 °C toughness.
Can G9Ni14 be formed, bent or molded?
Supplied as sand or investment castings; needs generous risering (high solidification shrinkage) and full quench-and-temper of the finished shape — cold forming is not a normal route.
What surface finishes work on G9Ni14?
Not anodizable; protect with shot blast plus epoxy/zinc-rich paint, or electroless nickel/plating for wet or outdoor service; machined sealing faces polish well.
G9Ni14 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 |
|---|---|---|
| Clow carbon for toughness and weldability | ≤ 0.1 | 0.08 |
| Si | ≤ 0.6 | 0.4 |
| Mn | 0.5 – 0.8 | 0.65 |
| P | ≤ 0.02 | 0.01 |
| S | ≤ 0.02 | 0.01 |
| NiEN designation Ni14 = 14/4 ≈ 3.5 % Ni | 3 – 4 | 3.5 |
| Crresidual | ≤ 0.3 | 0.1 |
| Moresidual | ≤ 0.2 | 0.05 |
| Curesidual | ≤ 0.3 | 0.1 |
| Vresidual | ≤ 0.05 | 0.01 |
| Fe | balance | — |
G9Ni14-QT — frequently asked
What is G9Ni14-QT used for?
G9Ni14-QT is typically used for cryogenic vessel castings, LNG equipment components and low-temperature valve and pump housings. In short: higher nickel than G9Ni10; 400 MPa cryogenic yield; cryogenic vessel casting grade.
What is the yield strength of G9Ni14-QT?
G9Ni14-QT has a typical yield strength of 400 MPa (58 ksi) and a tensile strength of 560 MPa (81.2 ksi) — weaker than 60% of steel grades. Strength varies by condition: see the 3 listed tempers.
Is G9Ni14-QT easy to machine?
Reasonably — machinability is rated good (55/100, better than 62% of steel grades). Machines like a Q&T low-alloy steel at ~170 HB — sharp carbide inserts, moderate speed, rigid setup; watch for skin scale and casting hard spots.
Can G9Ni14-QT be welded?
Yes — weldability is rated good (65/100). Weldable with low-hydrogen SMAW/GTAW using matching 3.5Ni or Ni-base consumables, preheat 100–150 °C, interpass control and PWHT ~580–620 °C; avoid high heat input to protect −100 °C toughness.
What surface finishes work on G9Ni14-QT?
Not anodizable; protect with shot blast plus epoxy/zinc-rich paint, or electroless nickel/plating for wet or outdoor service; machined sealing faces polish well.
Can G9Ni14-QT be formed, bent or molded?
Supplied as sand or investment castings; needs generous risering (high solidification shrinkage) and full quench-and-temper of the finished shape — cold forming is not a normal route.
What is the maximum service temperature of G9Ni14-QT?
G9Ni14-QT is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between G9Ni14-QT and G9Ni14 QT-HS?
QT is the default condition — standard delivery condition for EN 10213 low-temperature valve and pump castings needing −100 °C toughness with Rp0.2 ≥ 360 MPa. QT-HS: same heat treatment on heavy-wall castings; reduced cooling rate lowers guaranteed yield strength and mid-wall toughness. Yield strength is 400 MPa in QT versus 370 MPa in QT-HS.
Sources
- EN 10213 — Steel castings for pressure purposes (low-temperature grades, 1.5638) — CEN (2016)
- EN 10027-1 / EN 10213-3 designation and mechanical property tables — CEN (1995)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels and High-Performance Alloys (cast low-alloy and Ni steels) — ASM International (1990)
- EN 13445-3 — Unfired pressure vessels, design (physical property data for ferritic steels) — CEN (2021)
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.