Steel A439 Type D-2
ASTM A439 Type D-2 · EN EN-GJSA-XNiCr20-2
ASTM A439 Type D-2 is an austenitic nickel ductile (Ni-Resist) cast iron with nodular graphite in a 20 % Ni austenite matrix, equivalent to EN-GJSA-XNiCr20-2.
Reference datasheet — A439 Type D-2 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 D-2 condition
A439 Type D-2 tempers and conditions
A439 Type D-2 is supplied in 12 conditions, soft to hard. D-2 is the default FabDigit quotes; the values on this page are for it.
Compare all 12 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Type D-2C | Most ductile and reliably non-magnetic A439 grade; used for pressure-tight housings, instrument and non-magnetic parts. | 215 | 430 | 28 | 145 HB | 13 W/m·K |
ASTM A571 Type D-2M Class 2 or 4 | Same cryogenic Ni-Mn iron at a slightly lower strength/ductility acceptance class, typically for heavier sections. | 215 | 440 | 30 | 150 HB | — |
Type D-2S | Higher-silicon version of D-2 for better scaling/growth resistance in hot exhaust and furnace hardware. | 220 | 420 | 12 | 170 HB | 13 W/m·K |
Type D-3A | Lower-chromium D-3 for better ductility and machinability where carbide-forming Cr is not needed. | 220 | 400 | 14 | 160 HB | 13 W/m·K |
Type D-5 | Use where minimum thermal expansion and dimensional stability matter (machine tools, optical/scientific mounts, glass moulds). | 220 | 400 | 25 | 155 HB | 13 W/m·K |
Type D-5B | Chromium-bearing 35Ni grade for hot gas and furnace parts needing higher strength and oxidation resistance than D-5. | 225 | 410 | 8 | 165 HB | 13 W/m·K |
Type D-3 | Choose for lower thermal expansion than D-2 with good thermal-shock and dimensional stability in hot service. | 230 | 410 | 8 | 170 HB | 13 W/m·K |
ASTM A571 Type D-2M Class 1 or 3 | Pressure-containing LNG/cryogenic valve and pump castings requiring high ductility and impact energy down to −196 °C. | 230 | 470 | 35 | 145 HB | — |
Type D-5S | Best A439 grade for cyclic high-temperature exhaust/turbine hardware to ~870 °C with useful ductility. | 235 | 430 | 12 | 160 HB | 13 W/m·K |
D-2Default Type D-2 | General-purpose Ni-Resist ductile iron for seawater pumps, valves and turbocharger housings. | 250 | 450 | 12 | 170 HB | 13 W/m·K |
Type D-2B | Pick when extra oxidation, growth and erosion resistance at temperature is wanted and slightly lower ductility is acceptable. | 255 | 460 | 9 | 180 HB | 13 W/m·K |
Type D-4 | Hard, high-silicon/chromium grade for maximum scaling and growth resistance; accept near-zero ductility. | 280 | 430 | 2 | 235 HB | 13 W/m·K |
What is A439 Type D-2?
ASTM A439 Type D-2 is an austenitic nickel ductile (Ni-Resist) cast iron with nodular graphite in a 20 % Ni austenite matrix, equivalent to EN-GJSA-XNiCr20-2. It combines 250 MPa yield, 450 MPa tensile and 12 % elongation at 170 HB with corrosion resistance and service to 760 °C, so it is used for sand-cast pump casings, valve bodies and turbine housings in marine and chemical plant. Thermal conductivity is low at 12.6 W/m·K and machinability is limited (score 45) because the austenite work-hardens; A436 Type 1 gray Ni-Resist is cheaper where ductility is not needed. A439 Type D-2 has a density of 7.4 g/cm³ (0.267 lb/in³), lighter than 98% of steel grades. It melts at 1,150°C (2,102 °F). A439 Type D-2 has a yield strength of 250 MPa (36.3 ksi) and a tensile strength of 450 MPa (65.3 ksi) — weaker than 94% of steel grades. Elongation at break is 12% and the elastic modulus is 120 GPa (17.4 Msi).
What is A439 Type D-2 used for?
- pump casings
- valve bodies
- turbine housings
- seawater equipment
Advantages
- High service temperature — 760°C (1,400 °F), better than 100% of steel grades
- Good corrosion resistance — 60/100, better than 99% of steel grades
Limitations
- Low electrical conductivity — 1.7 % IACS, worse than 100% of steel grades
- Low stiffness — 120 GPa (17.4 Msi), worse than 99% of steel grades
- Poor heat conductor — 12.6 W/m·K (7.28 BTU/hr·ft·°F), worse than 99% of steel grades
- Low strength — 250 MPa (36.3 ksi), worse than 94% of steel grades
- High embodied carbon — 3.5 kg CO₂/kg, worse than 93% of steel grades
A439 Type D-2 properties
Typical room-temperature values for A439 Type D-2-D-2; bars are the position among steel grades.
Physical3
A439 Type D-2 has a density of 7.4 g/cm³ (0.267 lb/in³), lighter than 98% of steel grades. It melts at 1,150°C (2,102 °F).
Mechanical13
A439 Type D-2 has a yield strength of 250 MPa (36.3 ksi) and a tensile strength of 450 MPa (65.3 ksi) — weaker than 94% of steel grades. Elongation at break is 12% and the elastic modulus is 120 GPa (17.4 Msi).
Thermal6
A439 Type D-2 is rated for continuous service to 760°C (1,400 °F). It conducts heat at 12.6 W/m·K (7.28 BTU/hr·ft·°F), worse than 99% of steel grades. Thermal expansion is 18.7 µm/m·K (10.4 µin/in·°F).
Electrical3
A439 Type D-2 conducts electricity at 1.7 % IACS, worse than 100% of steel grades.
Chemical & Environmental3
Corrosion resistance is good (60/100), better than 99% of steel grades.
Sustainability4
Producing a kilogram of A439 Type D-2 takes about 45 MJ of energy and emits 3.5 kg of CO₂ — more than 93% of steel grades. Typical recycled content is 60%.
Manufacturability6
A439 Type D-2's machinability is fair (45/100, worse than 65% of steel grades); weldability fair (50/100).
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. A439 Type D-2 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with A439 Type D-2
Is A439 Type D-2 easy to machine?
Machines like a tough ductile iron but the austenite work-hardens: use rigid setups, positive-rake carbide, moderate speed and heavy positive feed to stay under the hardened skin; high-Si D-4/D-5S are abrasive and need ceramic/CBN.
Can A439 Type D-2 be welded?
Weldable with Ni-Fe or pure-Ni electrodes (ENiFe-CI/ENi-CI), 300–350 °C preheat for high-Cr types, short stringer beads and peening; low-Cr D-2C and D-2M are the most weld-friendly.
Can A439 Type D-2 be formed, bent or molded?
Sand-cast only — good fluidity with 20–35 % Ni, but requires generous risering (shrinkage ~2 %), Mg treatment for nodularity and controlled section cooling to avoid carbides.
A439 Type D-2 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 |
|---|---|---|
| Ctotal carbon, ASTM A439 Type D-2 | ≤ 3 | 2.8 |
| Si | 1.5 – 3 | 2.2 |
| Mn | 0.7 – 1.25 | 1 |
| Ni | 18 – 22 | 20 |
| Cr | 1.75 – 2.75 | 2.2 |
| P | ≤ 0.08 | — |
| Mgnodulizing residual, not specified in A439 but typical | 0.03 – 0.08 | 0.05 |
| Fe | balance | — |
What surface finishes work on A439 Type D-2?
Takes paint, epoxy and Ni/Cr plating after abrasive blast; graphite nodules limit mirror polish, and no anodizing applies — surfaces are usually left bare in seawater duty.
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 A439 Type D-2 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- EN-GJSA-XNiCr20-2
- Similar grades
- 2892
How much does A439 Type D-2 cost?
A439 Type D-2 is a high-cost steel ($$$$), pricier than about 78% 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.
A439 Type D-2 — frequently asked
What is A439 Type D-2 used for?
A439 Type D-2 is typically used for pump casings, valve bodies, turbine housings and seawater equipment. In short: ductile austenitic Ni-Resist; 12 % elongation at 760 °C rating; marine corrosion service.
What is the yield strength of A439 Type D-2?
A439 Type D-2 has a typical yield strength of 250 MPa (36.3 ksi) and a tensile strength of 450 MPa (65.3 ksi) — weaker than 94% of steel grades. Strength varies by condition: see the 12 listed tempers.
Is A439 Type D-2 easy to machine?
Reasonably — machinability is rated fair (45/100, worse than 65% of steel grades). Machines like a tough ductile iron but the austenite work-hardens: use rigid setups, positive-rake carbide, moderate speed and heavy positive feed to stay under the hardened skin; high-Si D-4/D-5S are abrasive and need ceramic/CBN.
Can A439 Type D-2 be welded?
With care — weldability is rated fair (50/100). Weldable with Ni-Fe or pure-Ni electrodes (ENiFe-CI/ENi-CI), 300–350 °C preheat for high-Cr types, short stringer beads and peening; low-Cr D-2C and D-2M are the most weld-friendly.
What surface finishes work on A439 Type D-2?
Takes paint, epoxy and Ni/Cr plating after abrasive blast; graphite nodules limit mirror polish, and no anodizing applies — surfaces are usually left bare in seawater duty.
Can A439 Type D-2 be formed, bent or molded?
Sand-cast only — good fluidity with 20–35 % Ni, but requires generous risering (shrinkage ~2 %), Mg treatment for nodularity and controlled section cooling to avoid carbides.
What is the maximum service temperature of A439 Type D-2?
A439 Type D-2 is rated for continuous use to about 760°C (1,400 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between A439 Type D-2 D-2 and A439 Type D-2 D-2C?
D-2 is the default condition — general-purpose Ni-Resist ductile iron for seawater pumps, valves and turbocharger housings. D-2C: most ductile and reliably non-magnetic A439 grade; used for pressure-tight housings, instrument and non-magnetic parts. Yield strength is 250 MPa in D-2 versus 215 MPa in D-2C.
How much does A439 Type D-2 cost?
A439 Type D-2 is a high-cost steel ($$$$), pricier than about 78% 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
- ASTM A439/A439M — Austenitic Ductile Iron Castings — ASTM International (2018)
- ASTM A571/A571M — Austenitic Ductile Iron Castings for Pressure-Containing Parts Suitable for Low-Temperature Service — ASTM International (2019)
- EN 13835 — Founding: Austenitic Cast Irons — CEN (2012)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- Engineering Properties and Applications of Ni-Resist and Ductile Ni-Resist Alloys — Nickel Institute (2020)
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.