Stainless Steel 12Kh18N9TL SA+ST
Heat-treated state
ASTM CF8C
SA+ST = solution treated plus stabilizing anneal 850–900 °C
Pick for long-term service at 450–750 °C or in strongly oxidizing acids, where all carbon must be fixed as TiC before service.
Values for the SA+ST condition
Other 12Kh18N9TL tempers and conditions
12Kh18N9TL is listed in 5 conditions; see the grade overview at 12Kh18N9TL.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Homogenizing anneal 1100–1150 °C, air cooled | For heavy-section castings where water quenching would crack; evens out dendritic segregation with slightly lower ductility than water-quenched material. | 230 | 480 | 32 | 148 HB | 2.4 % IACS |
SADefault Solution treated | Standard supply condition for corrosion service — carbides dissolved, maximum ductility and intergranular corrosion resistance. | 240 | 490 | 35 | 150 HB | — |
Stress relieved | Low-temperature stress relief used after weld repair of finished castings when full re-solution treatment is impossible; Ti stabilization protects the HAZ. | 245 | 485 | 30 | 155 HB | 2.4 % IACS |
As fabricated | Use only for non-critical, non-corrosive structural castings; grain-boundary carbides and casting stresses remain. | 250 | 470 | 25 | 165 HB | 2.3 % IACS |
SA+STThis page Solution treated plus stabilizing anneal 850–900 °C | Pick for long-term service at 450–750 °C or in strongly oxidizing acids, where all carbon must be fixed as TiC before service. | 255 | 500 | 30 | 155 HB | 2.4 % IACS |
What is 12Kh18N9TL SA+ST?
12Kh18N9TL SA+ST is 12Kh18N9TL heat treated to SA+ST — pick for long-term service at 450–750 °C or in strongly oxidizing acids, where all carbon must be fixed as TiC before service. 12Kh18N9TL SA+ST has a yield strength of 255 MPa (37 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 87% of stainless steel grades. Elongation at break is 30% and the elastic modulus is 193 GPa (28 Msi). 12Kh18N9TL SA+ST has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 65% of stainless steel grades. It melts at 1,400°C (2,552 °F). SA is the default condition FabDigit quotes; SA+ST is available on request or by drawing note.
Advantages
- Readily welded — 82/100, better than 84% of stainless steel grades
- Low embodied carbon — 3.8 kg CO₂/kg, better than 77% of stainless steel grades
Limitations
- Low strength — 255 MPa (37 ksi), worse than 87% of stainless steel grades
- Limited formability — 23/100, worse than 82% of stainless steel grades
- Hard to polish — 60/100, worse than 80% of stainless steel grades
12Kh18N9TL SA+ST properties
Typical room-temperature values for 12Kh18N9TL SA+ST; 22 are specific to this condition. Other listed values are 12Kh18N9TL reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
12Kh18N9TL SA+ST has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 65% of stainless steel grades. It melts at 1,400°C (2,552 °F).
Mechanical15
12Kh18N9TL SA+ST has a yield strength of 255 MPa (37 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 87% of stainless steel grades. Elongation at break is 30% and the elastic modulus is 193 GPa (28 Msi).
Thermal6
12Kh18N9TL SA+ST is rated for continuous service to 700°C (1,292 °F). It conducts heat at 15.5 W/m·K (8.96 BTU/hr·ft·°F), better than 53% of stainless steel grades. Thermal expansion is 16.5 µm/m·K (9.17 µin/in·°F).
Electrical3
12Kh18N9TL SA+ST conducts electricity at 2.4 % IACS, better than 67% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (68/100), better than 63% of stainless steel grades.
Sustainability4
Producing a kilogram of 12Kh18N9TL SA+ST takes about 57 MJ of energy and emits 3.8 kg of CO₂ — more than 62% of stainless steel grades. Typical recycled content is 70%.
Manufacturability8
12Kh18N9TL SA+ST's machinability is poor (32/100, worse than 62% of stainless steel grades); weldability very good (82/100); formability poor (23/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 12Kh18N9TL SA+ST
Is 12Kh18N9TL easy to machine?
Gummy and work-hardening: use sharp positive-rake carbide, rigid setups, 60–110 m/min, heavy feed and flood coolant; avoid dwelling and expect abrasive TiC inclusions.
Can 12Kh18N9TL be welded?
Readily welded by GTAW/SMAW with matching Ti- or Nb-stabilized filler (e.g. 08Kh19N10T / ER321 / ER347); low heat input, no preheat, post-weld solution or stabilizing anneal optional thanks to Ti.
Can 12Kh18N9TL be formed, bent or molded?
Sand or investment cast with generous risering (≈2.3 % solidification shrinkage), controlled 2–8 FN ferrite for hot-tear resistance, and slow, well-fed thick sections.
What surface finishes work on 12Kh18N9TL?
Grit blast, pickle in HNO₃/HF then passivate in nitric acid; electropolishing improves hygiene surfaces — no anodizing, plating rarely needed.
12Kh18N9TL 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 |
|---|---|---|
| CGOST 977-88 | ≤ 0.12 | 0.09 |
| Si | 0.2 – 1 | 0.6 |
| Mn | 1 – 2 | 1.5 |
| Cr | 17 – 20 | 18.5 |
| Ni | 8 – 11 | 9.5 |
| Tistabilizer, ≈5×C minimum in practice | 0.4 – 0.8 | 0.6 |
| S | ≤ 0.03 | — |
| P | ≤ 0.04 | — |
| Curesidual | ≤ 0.3 | — |
| Fe | balance | — |
12Kh18N9TL SA+ST — frequently asked
What is 12Kh18N9TL SA+ST used for?
12Kh18N9TL SA+ST is typically used for high-temperature valve castings, exhaust system castings and welded pressure castings. In short: stabilized cast austenitic; CF8C equivalent; 650 °C service castings.
What is the yield strength of 12Kh18N9TL SA+ST?
12Kh18N9TL SA+ST has a typical yield strength of 255 MPa (37 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 87% of stainless steel grades. Strength varies by condition: see the 5 listed tempers.
Is 12Kh18N9TL SA+ST easy to machine?
Not especially — machinability is rated poor (32/100, worse than 62% of stainless steel grades). Gummy and work-hardening: use sharp positive-rake carbide, rigid setups, 60–110 m/min, heavy feed and flood coolant; avoid dwelling and expect abrasive TiC inclusions.
Can 12Kh18N9TL SA+ST be welded?
Yes — weldability is rated very good (82/100). Readily welded by GTAW/SMAW with matching Ti- or Nb-stabilized filler (e.g. 08Kh19N10T / ER321 / ER347); low heat input, no preheat, post-weld solution or stabilizing anneal optional thanks to Ti.
What surface finishes work on 12Kh18N9TL SA+ST?
Grit blast, pickle in HNO₃/HF then passivate in nitric acid; electropolishing improves hygiene surfaces — no anodizing, plating rarely needed.
Can 12Kh18N9TL SA+ST be formed, bent or molded?
Sand or investment cast with generous risering (≈2.3 % solidification shrinkage), controlled 2–8 FN ferrite for hot-tear resistance, and slow, well-fed thick sections.
What is the maximum service temperature of 12Kh18N9TL SA+ST?
12Kh18N9TL SA+ST is rated for continuous use to about 700°C (1,292 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 12Kh18N9TL-SA and 12Kh18N9TL-F?
SA is the default condition — standard supply condition for corrosion service — carbides dissolved, maximum ductility and intergranular corrosion resistance. F: use only for non-critical, non-corrosive structural castings; grain-boundary carbides and casting stresses remain. Yield strength is 240 MPa in SA versus 250 MPa in F.
Sources
- GOST 977-88 — Steel castings, general specifications — Gosstandart (1988)
- ASTM A351/A351M — Castings, austenitic, for pressure-containing parts (CF8C) — ASTM International (2023)
- ASM Handbook Vol.1 — Properties of Cast Stainless Steels — ASM International (1990)
- Steel Castings Handbook, 6th ed. — SFSA / ASM International (1995)
- Corrosion Handbook (stainless grade behaviour, 321/347 analogues) — Outokumpu (2015)
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.