Stainless Steel 1.3967-AC (Spheroidize annealed)
Heat-treated state
EN 1.3967
Only for rough stock or non-corrosive structural parts — interdendritic carbide/nitride segregation lowers ductility and pitting resistance; not a normal delivery condition.
Values for the AC condition
Other 1.3967 tempers and conditions
1.3967 is listed in 3 conditions; see the grade overview at 1.3967.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ATDefault Solution annealed (≈1050–1120 °C) and water quenched | Standard delivery condition for all castings: maximum corrosion resistance, fully austenitic and non-magnetic, good strength/ductility balance. | 380 | 690 | 32 | 220 HB | — |
hot isostatically pressed, then solution annealed and quenched | Choose for pressure-retaining or fatigue-critical castings where micro-shrinkage must be closed — higher ductility, toughness and fatigue life at same strength level. | 390 | 720 | 38 | 225 HB | 1.9 % IACS |
ACThis page Spheroidize annealed | Only for rough stock or non-corrosive structural parts — interdendritic carbide/nitride segregation lowers ductility and pitting resistance; not a normal delivery condition. | 400 | 640 | 18 | 21 HRC | 1.9 % IACS |
What is 1.3967-AC?
1.3967-AC is 1.3967 heat treated to AC — only for rough stock or non-corrosive structural parts — interdendritic carbide/nitride segregation lowers ductility and pitting resistance; not a normal delivery condition. 1.3967-AC has a yield strength of 400 MPa (58 ksi) and a tensile strength of 640 MPa (92.8 ksi) — stronger than 57% of stainless steel grades. Elongation at break is 18% and the elastic modulus is 193 GPa (28 Msi). 1.3967-AC has a density of 7.9 g/cm³ (0.285 lb/in³), heavier than 68% of stainless steel grades. It melts at 1,370°C (2,498 °F). AT is the default condition FabDigit quotes; AC is available on request or by drawing note.
Limitations
- Difficult to machine — 20/100, worse than 98% of stainless steel grades
- Low electrical conductivity — 1.9 % IACS, worse than 87% of stainless steel grades
- Limited formability — 20/100, worse than 86% of stainless steel grades
- Limited ductility — 18%, worse than 83% of stainless steel grades
- Difficult to weld — 50/100, worse than 77% of stainless steel grades
1.3967-AC properties
Typical room-temperature values for 1.3967-AC; 24 are specific to this condition. Other listed values are 1.3967 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
1.3967-AC has a density of 7.9 g/cm³ (0.285 lb/in³), heavier than 68% of stainless steel grades. It melts at 1,370°C (2,498 °F).
Mechanical16
1.3967-AC has a yield strength of 400 MPa (58 ksi) and a tensile strength of 640 MPa (92.8 ksi) — stronger than 57% of stainless steel grades. Elongation at break is 18% and the elastic modulus is 193 GPa (28 Msi).
Thermal6
1.3967-AC is rated for continuous service to 450°C (842 °F). It conducts heat at 13.5 W/m·K (7.8 BTU/hr·ft·°F), worse than 83% of stainless steel grades. Thermal expansion is 15.5 µm/m·K (8.61 µin/in·°F).
Electrical3
1.3967-AC conducts electricity at 1.9 % IACS, worse than 87% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (65/100), better than 56% of stainless steel grades.
Sustainability4
Producing a kilogram of 1.3967-AC takes about 57 MJ of energy and emits 4.6 kg of CO₂ — more than 62% of stainless steel grades. Typical recycled content is 65%.
Manufacturability7
1.3967-AC's machinability is poor (20/100, worse than 98% of stainless steel grades); weldability fair (50/100); formability poor (20/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 1.3967-AC
Is 1.3967 easy to machine?
Very difficult: heavy work hardening from the 0.4 % N austenite — use rigid setups, sharp positive-rake carbide/ceramic tools, low speed (30–60 m/min), heavy positive feed and copious high-pressure coolant; never dwell or rub.
Can 1.3967 be welded?
Weld with matching high-N/Nb or over-alloyed Ni-base filler (e.g. 21-16-5-3 or ERNiCrMo-3), low heat input, interpass < 150 °C, Ar+N₂ shielding to limit nitrogen loss; solution anneal + quench after major repair welds where possible.
Can 1.3967 be formed, bent or molded?
Sand or investment cast with tight melt control (pressurised N addition, low S/O) to avoid nitrogen pinholes; generous risering for the low thermal conductivity, and HIP is recommended for pressure-tight sections.
What surface finishes work on 1.3967?
Pickle and passivate (HNO₃/HF) after heat treatment to restore the passive film; takes a good mechanical/electro-polish, and shot peening improves fatigue without affecting the non-magnetic character.
1.3967 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 |
|---|---|---|
| Cextra-low carbon | ≤ 0.03 | 0.02 |
| Si | ≤ 1 | 0.6 |
| Mnraises N solubility | 4 – 6 | 5 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.02 | 0.01 |
| Cr | 20 – 22 | 21 |
| Ni | 15 – 17 | 16 |
| Mo | 2.5 – 3.5 | 3 |
| Nbstabiliser, grain refinement | 0.1 – 0.3 | 0.2 |
| Nprimary strengthening element | 0.3 – 0.5 | 0.4 |
| Fe | balance | — |
1.3967-AC — frequently asked
What is 1.3967-AC used for?
1.3967-AC is typically used for pump casings and impellers, valve bodies and bonnets, high-strength corrosion-resistant pressure castings, non-magnetic machinery castings, HIP'd pressure-tight housings and chemical process fittings and manifolds. In short: strongest cast austenitic here; nitrogen-strengthened, non-magnetic; hardest of family to machine.
What is the yield strength of 1.3967-AC?
1.3967-AC has a typical yield strength of 400 MPa (58 ksi) and a tensile strength of 640 MPa (92.8 ksi) — stronger than 57% of stainless steel grades. Strength varies by condition: see the 3 listed tempers.
Is 1.3967-AC easy to machine?
Not especially — machinability is rated poor (20/100, worse than 98% of stainless steel grades). Very difficult: heavy work hardening from the 0.4 % N austenite — use rigid setups, sharp positive-rake carbide/ceramic tools, low speed (30–60 m/min), heavy positive feed and copious high-pressure coolant; never dwell or rub.
Can 1.3967-AC be welded?
With care — weldability is rated fair (50/100). Weld with matching high-N/Nb or over-alloyed Ni-base filler (e.g. 21-16-5-3 or ERNiCrMo-3), low heat input, interpass < 150 °C, Ar+N₂ shielding to limit nitrogen loss; solution anneal + quench after major repair welds where possible.
What surface finishes work on 1.3967-AC?
Pickle and passivate (HNO₃/HF) after heat treatment to restore the passive film; takes a good mechanical/electro-polish, and shot peening improves fatigue without affecting the non-magnetic character.
Can 1.3967-AC be formed, bent or molded?
Sand or investment cast with tight melt control (pressurised N addition, low S/O) to avoid nitrogen pinholes; generous risering for the low thermal conductivity, and HIP is recommended for pressure-tight sections.
What is the maximum service temperature of 1.3967-AC?
1.3967-AC is rated for continuous use to about 450°C (842 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 1.3967-AT and 1.3967-AC?
AT is the default condition — standard delivery condition for all castings: maximum corrosion resistance, fully austenitic and non-magnetic, good strength/ductility balance. AC: only for rough stock or non-corrosive structural parts — interdendritic carbide/nitride segregation lowers ductility and pitting resistance; not a normal delivery condition. Yield strength is 380 MPa in AT versus 400 MPa in AC.
Sources
- SEW 400 / DIN EN 10283 — corrosion-resistant steel castings — VDEh / CEN (2010)
- DIN 17440 / DIN EN 10088 designation data for X2CrNiMnMoNNb21-16-5-3 (1.3964) — DIN/CEN (2014)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASM Specialty Handbook — Stainless Steels — ASM International (1994)
- High-nitrogen non-magnetic austenitic steel (P900/1.3964 family) datasheets — Böhler / Energietechnik steel producers (2020)
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.