Steel GX9Ni5
EN 1.5681
GX9Ni5 (EN 1.5681) is a cast low-alloy steel with about 5 % nickel, supplied quenched and tempered, normalized and tempered or annealed, and used where good low-temperature impact toughness is required in pressure-containing castings.
Reference datasheet — GX9Ni5 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the +QT condition
GX9Ni5 tempers and conditions
GX9Ni5 is supplied in 3 conditions, soft to hard. +QT is the default FabDigit quotes; the values on this page are for it.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Interim foundry condition for rough machining or weld repair; final +QT/+NT treatment is required before service. | 310 | 490 | 27 | 150 HB | 5.3 % IACS |
Normalized and tempered | Chosen for thick or complex castings where quenching risks distortion/cracking; slightly lower strength than +QT. | 370 | 540 | 25 | 165 HB | 5.2 % IACS |
+QTDefault Quenched and tempered | Standard delivery condition for pressure castings needing guaranteed KV ≥ 27 J at -100 °C. | 400 | 570 | 24 | 175 HB | 5.2 % IACS |
What is GX9Ni5?
GX9Ni5 (EN 1.5681) is a cast low-alloy steel with about 5 % nickel, supplied quenched and tempered, normalized and tempered or annealed, and used where good low-temperature impact toughness is required in pressure-containing castings. Typical properties are 400 MPa yield, 570 MPa tensile, 24 % elongation and 175 HB in sand or investment cast pump, valve and offshore parts. The steel is tough and work-hardening, so metal removal is slower than on plain carbon cast steel, and it corrodes like carbon steel. G9Ni10 is the obvious alternative when service temperature drops further and more nickel is needed. GX9Ni5 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). GX9Ni5 has a yield strength of 400 MPa (58 ksi) and a tensile strength of 570 MPa (82.7 ksi) — weaker than 60% of steel grades. Elongation at break is 24% and the elastic modulus is 205 GPa (29.7 Msi).
What is GX9Ni5 used for?
- low-temperature pump and valve castings
- pressure equipment components
- offshore equipment castings
Advantages
- Tough — resists crack growth — 130 MPa·√m (118.3 ksi·√in), better than 89% of steel grades
Limitations
- High embodied carbon — 2.6 kg CO₂/kg, worse than 87% of steel grades
- Low electrical conductivity — 5.2 % IACS, worse than 81% of steel grades
- Poor heat conductor — 33 W/m·K (19.1 BTU/hr·ft·°F), worse than 80% of steel grades
- Limited formability — 20/100, worse than 80% of steel grades
GX9Ni5 properties
Typical room-temperature values for GX9Ni5-+QT; bars are the position among steel grades.
Physical3
GX9Ni5 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
GX9Ni5 has a yield strength of 400 MPa (58 ksi) and a tensile strength of 570 MPa (82.7 ksi) — weaker than 60% of steel grades. Elongation at break is 24% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
GX9Ni5 is rated for continuous service to 350°C (662 °F). It conducts heat at 33 W/m·K (19.1 BTU/hr·ft·°F), worse than 80% of steel grades. Thermal expansion is 11.5 µm/m·K (6.39 µin/in·°F).
Electrical3
GX9Ni5 conducts electricity at 5.2 % IACS, worse than 81% of steel grades.
Chemical & Environmental2
Corrosion resistance is poor (17/100), better than 81% of steel grades.
Sustainability4
Producing a kilogram of GX9Ni5 takes about 34 MJ of energy and emits 2.6 kg of CO₂ — more than 82% of steel grades. Typical recycled content is 65%.
Manufacturability8
GX9Ni5's machinability is fair (50/100, worse than 53% of steel grades); weldability good (65/100); formability poor (20/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the steel family
Yield strength against density for every steel grade FabDigit runs. GX9Ni5 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with GX9Ni5
Is GX9Ni5 easy to machine?
Tough, work-hardening Ni steel — use rigid setups, sharp positive-rake carbide, moderate speed with heavy feed; leave stock for finish cuts after final heat treatment.
Can GX9Ni5 be welded?
Readily welded with low-hydrogen 2.5–5 Ni or Ni-base consumables; preheat ~100–150 °C, limit interpass, and re-temper (PWHT) weld-repaired castings.
Can GX9Ni5 be formed, bent or molded?
Supplied as sand/investment casting — control feeding and use risers/chills for sound heavy sections; hot straightening should be followed by re-heat treatment.
GX9Ni5 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 |
| Niprovides low-temperature toughness | 4 – 5 | 4.7 |
| Crresidual | ≤ 0.3 | 0.1 |
| Moresidual | ≤ 0.2 | 0.05 |
| Curesidual | ≤ 0.3 | 0.1 |
| Vresidual | ≤ 0.05 | 0.02 |
| Fe | balance |
What surface finishes work on GX9Ni5?
No anodizing; protect with shot blast plus epoxy paint, zinc/aluminium metallizing, or electroless nickel for cryogenic service exteriors.
Surface treatments FabDigit runs on steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Organic Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel GX9Ni5 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- 1.5681
How much does GX9Ni5 cost?
GX9Ni5 is a premium-cost steel ($$$), cheaper than about 51% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
GX9Ni5 — frequently asked
What is GX9Ni5 used for?
GX9Ni5 is typically used for low-temperature pump and valve castings, pressure equipment components and offshore equipment castings. In short: 5 % Ni cast steel; low-temperature toughness; readily weldable casting.
What is the yield strength of GX9Ni5?
GX9Ni5 has a typical yield strength of 400 MPa (58 ksi) and a tensile strength of 570 MPa (82.7 ksi) — weaker than 60% of steel grades. Strength varies by condition: see the 3 listed tempers.
Is GX9Ni5 easy to machine?
Reasonably — machinability is rated fair (50/100, worse than 53% of steel grades). Tough, work-hardening Ni steel — use rigid setups, sharp positive-rake carbide, moderate speed with heavy feed; leave stock for finish cuts after final heat treatment.
Can GX9Ni5 be welded?
Yes — weldability is rated good (65/100). Readily welded with low-hydrogen 2.5–5 Ni or Ni-base consumables; preheat ~100–150 °C, limit interpass, and re-temper (PWHT) weld-repaired castings.
What surface finishes work on GX9Ni5?
No anodizing; protect with shot blast plus epoxy paint, zinc/aluminium metallizing, or electroless nickel for cryogenic service exteriors.
Can GX9Ni5 be formed, bent or molded?
Supplied as sand/investment casting — control feeding and use risers/chills for sound heavy sections; hot straightening should be followed by re-heat treatment.
What is the maximum service temperature of GX9Ni5?
GX9Ni5 is rated for continuous use to about 350°C (662 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does GX9Ni5 cost?
GX9Ni5 is a premium-cost steel ($$$), cheaper than about 51% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- EN 10213 — Steel castings for pressure purposes (low-temperature grades) — CEN (2016)
- ASTM A352/A352M — Ferritic and martensitic steel castings for low-temperature service — ASTM (2018)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- Steel Castings Handbook — Steel Founders' Society of America / ASM (1995)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.