Stainless Steel ZG1Cr18Ni9Ti ST+SA
Heat-treated state
ASTM CF8C
ST+SA = solution treated then stabilizing anneal ~870–900 °C
Choose when the casting runs long-term in the 450–850 °C sensitization range or sees severe intergranular attack (nitric acid); the stabilizing anneal at 870–900 °C after solution treatment ties up carbon.
Values for the ST+SA condition
Other ZG1Cr18Ni9Ti tempers and conditions
ZG1Cr18Ni9Ti is listed in 4 conditions; see the grade overview at ZG1Cr18Ni9Ti.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
As fabricated | Lowest-cost condition for non-critical, low-corrosivity parts where carbide networks and residual casting stress are acceptable. | 240 | 470 | 25 | 165 HB | 2.3 % IACS |
STDefault Solution annealed | Standard supply condition: maximum ductility, toughness and corrosion resistance for valve bodies, pumps and pressure-containing castings. | 245 | 500 | 38 | 150 HB | — |
Hot isostatically pressed then solution treated | Specified for pressure-critical or fatigue-loaded castings where internal microporosity must be closed (RT film/UT class 1). | 250 | 520 | 45 | 150 HB | 2.3 % IACS |
ST+SAThis page Solution treated then stabilizing anneal ~870–900 °C | Choose when the casting runs long-term in the 450–850 °C sensitization range or sees severe intergranular attack (nitric acid); the stabilizing anneal at 870–900 °C after solution treatment ties up carbon. | 255 | 510 | 34 | 155 HB | 2.3 % IACS |
What is ZG1Cr18Ni9Ti ST+SA?
ZG1Cr18Ni9Ti ST+SA is ZG1Cr18Ni9Ti heat treated to ST+SA — choose when the casting runs long-term in the 450–850 °C sensitization range or sees severe intergranular attack (nitric acid); the stabilizing anneal at 870–900 °C after solution treatment ties up carbon. ZG1Cr18Ni9Ti ST+SA has a yield strength of 255 MPa (37 ksi) and a tensile strength of 510 MPa (74 ksi) — weaker than 87% of stainless steel grades. Elongation at break is 34% and the elastic modulus is 193 GPa (28 Msi). ZG1Cr18Ni9Ti ST+SA 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). ST is the default condition FabDigit quotes; ST+SA is available on request or by drawing note.
Advantages
- High service temperature — 850°C (1,562 °F), better than 80% of stainless steel grades
Limitations
- Low strength — 255 MPa (37 ksi), worse than 87% of stainless steel grades
- Limited formability — 24/100, worse than 82% of stainless steel grades
- Hard to polish — 60/100, worse than 80% of stainless steel grades
ZG1Cr18Ni9Ti ST+SA properties
Typical room-temperature values for ZG1Cr18Ni9Ti ST+SA; 22 are specific to this condition. Other listed values are ZG1Cr18Ni9Ti reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
ZG1Cr18Ni9Ti ST+SA 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).
Mechanical16
ZG1Cr18Ni9Ti ST+SA has a yield strength of 255 MPa (37 ksi) and a tensile strength of 510 MPa (74 ksi) — weaker than 87% of stainless steel grades. Elongation at break is 34% and the elastic modulus is 193 GPa (28 Msi).
Thermal6
ZG1Cr18Ni9Ti ST+SA is rated for continuous service to 850°C (1,562 °F). It conducts heat at 16 W/m·K (9.24 BTU/hr·ft·°F), better than 58% of stainless steel grades. Thermal expansion is 16.5 µm/m·K (9.17 µin/in·°F).
Electrical3
ZG1Cr18Ni9Ti ST+SA conducts electricity at 2.3 % IACS, better than 55% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (65/100), better than 56% of stainless steel grades.
Sustainability4
Producing a kilogram of ZG1Cr18Ni9Ti ST+SA takes about 53 MJ of energy and emits 4.5 kg of CO₂ — less than 67% of stainless steel grades. Typical recycled content is 70%.
Manufacturability8
ZG1Cr18Ni9Ti ST+SA's machinability is poor (34/100, worse than 55% of stainless steel grades); weldability very good (78/100); formability poor (24/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with ZG1Cr18Ni9Ti ST+SA
Is ZG1Cr18Ni9Ti easy to machine?
Gummy and work-hardening like 304 — use rigid setups, sharp positive-rake carbide, 60–110 m/min, heavy feed and flood coolant; skin sand/scale must be removed before finishing cuts.
Can ZG1Cr18Ni9Ti be welded?
Readily welded by GTAW/SMAW, but titanium burns out across the arc — use ER347/E347 (Nb-stabilized) or 308L filler; no post-weld anneal required thanks to stabilization.
Can ZG1Cr18Ni9Ti be formed, bent or molded?
Sand or investment cast at 1520–1560 °C with generous risering (≈2.3 % solidification shrinkage) and controlled 5–15 % delta ferrite to avoid hot tearing.
What surface finishes work on ZG1Cr18Ni9Ti?
Grit-blast, pickle in HNO₃/HF then passivate per ASTM A967; electropolish or mechanical polish for hygienic surfaces — no anodizing.
ZG1Cr18Ni9Ti 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 |
|---|---|---|
| C≤0.12 % per GB 2100 legacy ZG1Cr18Ni9Ti; ≤0.08 % in CF8C | ≤ 0.12 | 0.08 |
| Si | ≤ 1.5 | 1 |
| Mn | ≤ 2 | 1.2 |
| P | ≤ 0.04 | 0.03 |
| S | ≤ 0.04 | 0.03 |
| Cr | 17 – 20 | 18.5 |
| Ni | 8 – 11 | 9.5 |
| Ti≥5×C (stabilizer); CF8C uses Nb ≥8×C, ≤1.0 % instead | ≤ 0.8 | 0.5 |
| Moresidual only unless otherwise agreed | ≤ 0.5 | — |
| Fe | balance | — |
ZG1Cr18Ni9Ti ST+SA — frequently asked
What is ZG1Cr18Ni9Ti ST+SA used for?
ZG1Cr18Ni9Ti ST+SA is typically used for exhaust and manifold castings, high-temperature valve bodies and welded pressure castings. In short: highest service temperature here; stabilized CF8C equivalent; no post-weld anneal needed.
What is the yield strength of ZG1Cr18Ni9Ti ST+SA?
ZG1Cr18Ni9Ti ST+SA has a typical yield strength of 255 MPa (37 ksi) and a tensile strength of 510 MPa (74 ksi) — weaker than 87% of stainless steel grades. Strength varies by condition: see the 4 listed tempers.
Is ZG1Cr18Ni9Ti ST+SA easy to machine?
Not especially — machinability is rated poor (34/100, worse than 55% of stainless steel grades). Gummy and work-hardening like 304 — use rigid setups, sharp positive-rake carbide, 60–110 m/min, heavy feed and flood coolant; skin sand/scale must be removed before finishing cuts.
Can ZG1Cr18Ni9Ti ST+SA be welded?
Yes — weldability is rated very good (78/100). Readily welded by GTAW/SMAW, but titanium burns out across the arc — use ER347/E347 (Nb-stabilized) or 308L filler; no post-weld anneal required thanks to stabilization.
What surface finishes work on ZG1Cr18Ni9Ti ST+SA?
Grit-blast, pickle in HNO₃/HF then passivate per ASTM A967; electropolish or mechanical polish for hygienic surfaces — no anodizing.
Can ZG1Cr18Ni9Ti ST+SA be formed, bent or molded?
Sand or investment cast at 1520–1560 °C with generous risering (≈2.3 % solidification shrinkage) and controlled 5–15 % delta ferrite to avoid hot tearing.
What is the maximum service temperature of ZG1Cr18Ni9Ti ST+SA?
ZG1Cr18Ni9Ti ST+SA is rated for continuous use to about 850°C (1,562 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between ZG1Cr18Ni9Ti-ST and ZG1Cr18Ni9Ti-F?
ST is the default condition — standard supply condition: maximum ductility, toughness and corrosion resistance for valve bodies, pumps and pressure-containing castings. F: lowest-cost condition for non-critical, low-corrosivity parts where carbide networks and residual casting stress are acceptable. Yield strength is 245 MPa in ST versus 240 MPa in F.
Sources
- GB/T 2100 (incl. legacy GB 2100 ZG1Cr18Ni9Ti) (2017)
- ASTM A351/A351M — Castings, Austenitic, for Pressure-Containing Parts (CF8C) — ASTM International (2022)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys (Cast Stainless Steels) — ASM International (1990)
- Steel Castings Handbook, 6th ed. — Steel Founders' Society of America (1995)
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.