Stainless Steel ZG1Cr18Ni9
ASTM CF8
ZG1Cr18Ni9 is a Chinese cast austenitic stainless steel (18Cr-9Ni) used by foundries as the direct equivalent of ASTM CF8.
Reference datasheet — ZG1Cr18Ni9 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 ST condition
ZG1Cr18Ni9 tempers and conditions
ZG1Cr18Ni9 is supplied in 4 conditions, soft to hard. ST is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
As fabricated | Cheapest condition for non-pressure, non-corrosive brackets and general hardware; interdendritic carbides reduce corrosion resistance and ductility. | 245 | 480 | 30 | 160 HB | — |
STDefault Solution annealed | Standard supply condition for pressure-retaining valve and pump castings; carbides dissolved for maximum corrosion resistance and ductility. | 250 | 520 | 55 | 140 HB | — |
Solution annealed then low-temperature stress relieved | Used for thick or weld-repaired castings needing dimensional stability; kept below the sensitization range so corrosion resistance is preserved. | 255 | 515 | 50 | 145 HB | 2.4 % IACS |
Hot isostatically pressed then solution annealed | Choose for high-integrity pressure or cryogenic castings where shrinkage porosity must be closed to raise fatigue life and toughness. | 260 | 545 | 60 | 145 HB | — |
What is ZG1Cr18Ni9?
ZG1Cr18Ni9 is a Chinese cast austenitic stainless steel (18Cr-9Ni) used by foundries as the direct equivalent of ASTM CF8. Engineers specify it for valve and pump bodies because it combines general corrosion resistance (score 70) with high ductility — 250 MPa yield, 520 MPa tensile, 55 % elongation and 140 HB — and service to 760 °C. It is available as sand, investment and centrifugal castings, not wrought product. Machinability is low (score 35) and, with carbon above 0.03 %, as-welded castings can sensitize; use ZG0Cr18Ni9 / CF3 for as-welded corrosion service. ZG1Cr18Ni9 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). ZG1Cr18Ni9 has a yield strength of 250 MPa (36.3 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 91% of stainless steel grades. Elongation at break is 55% and the elastic modulus is 193 GPa (28 Msi).
What is ZG1Cr18Ni9 used for?
- valve bodies
- pump casings
- pipe fittings
- general corrosion-resistant castings
Advantages
- Ductile — tolerates forming and impact — 55%, better than 97% of stainless steel grades
- Readily welded — 85/100, better than 87% of stainless steel grades
Limitations
- Low strength — 250 MPa (36.3 ksi), worse than 91% of stainless steel grades
- Hard to polish — 60/100, worse than 80% of stainless steel grades
- Limited formability — 25/100, worse than 78% of stainless steel grades
ZG1Cr18Ni9 properties
Typical room-temperature values for ZG1Cr18Ni9-ST; bars are the position among stainless steel grades.
Physical3
ZG1Cr18Ni9 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
ZG1Cr18Ni9 has a yield strength of 250 MPa (36.3 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 91% of stainless steel grades. Elongation at break is 55% and the elastic modulus is 193 GPa (28 Msi).
Thermal6
ZG1Cr18Ni9 is rated for continuous service to 760°C (1,400 °F). It conducts heat at 16.2 W/m·K (9.36 BTU/hr·ft·°F), better than 64% of stainless steel grades. Thermal expansion is 17.3 µm/m·K (9.61 µin/in·°F).
Electrical3
ZG1Cr18Ni9 conducts electricity at 2.4 % IACS, better than 67% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is very good (70/100), better than 68% of stainless steel grades.
Sustainability4
Producing a kilogram of ZG1Cr18Ni9 takes about 55 MJ of energy and emits 4.5 kg of CO₂ — more than 50% of stainless steel grades. Typical recycled content is 75%.
Manufacturability8
ZG1Cr18Ni9's machinability is fair (35/100, better than 51% of stainless steel grades); weldability excellent (85/100); formability poor (25/100).
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 stainless steel family
Yield strength against density for every stainless steel grade FabDigit runs. ZG1Cr18Ni9 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with ZG1Cr18Ni9
Is ZG1Cr18Ni9 easy to machine?
Work-hardens and gums up: use rigid setups, sharp carbide inserts, positive rake, 60–120 m/min, heavy feed and copious coolant; avoid dwelling to prevent glazing.
Can ZG1Cr18Ni9 be welded?
Very good with ER308/E308 (or 308L for repair of low-carbon heats); no preheat, keep interpass low, back-purge and pickle/passivate the weld area.
Can ZG1Cr18Ni9 be formed, bent or molded?
Sand, investment and centrifugal casting all suitable; allow ~2.0–2.3% shrinkage, use generous risers/chills because of long freezing range and hot-tearing tendency.
ZG1Cr18Ni9 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 |
|---|---|---|
| CGB old grade sometimes allows ≤0.10 | ≤ 0.08 | 0.06 |
| SiGB/T 2100 often ≤1.50 | ≤ 2 | 1.2 |
| Mn | ≤ 1.5 | 1 |
| P | ≤ 0.04 | 0.03 |
| SGB/T 2100 ZG07Cr19Ni9: S ≤0.030 | ≤ 0.04 | 0.02 |
| Cr | 18 – 21 | 19 |
| Ni | 8 – 11 | 9 |
| Moresidual only; add Mo → CF8M/ZG07Cr19Ni10Mo | ≤ 0.5 | |
| Fe | balance |
What surface finishes work on ZG1Cr18Ni9?
Shot blast and pickle (HNO₃-HF) then passivate; electropolishing gives best hygienic finish, plating and painting are rarely needed.
Surface treatments FabDigit runs on stainless 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).
Passivation
Organic Coating
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Stainless Steel ZG1Cr18Ni9 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- CF8
How much does ZG1Cr18Ni9 cost?
ZG1Cr18Ni9 is a premium-cost stainless 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.
ZG1Cr18Ni9 — frequently asked
What is ZG1Cr18Ni9 used for?
ZG1Cr18Ni9 is typically used for valve bodies, pump casings, pipe fittings and general corrosion-resistant castings. In short: baseline cast austenitic; CF8 equivalent; very high cast ductility.
What is the yield strength of ZG1Cr18Ni9?
ZG1Cr18Ni9 has a typical yield strength of 250 MPa (36.3 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 91% of stainless steel grades. Strength varies by condition: see the 4 listed tempers.
Is ZG1Cr18Ni9 easy to machine?
Not especially — machinability is rated fair (35/100, better than 51% of stainless steel grades). Work-hardens and gums up: use rigid setups, sharp carbide inserts, positive rake, 60–120 m/min, heavy feed and copious coolant; avoid dwelling to prevent glazing.
Can ZG1Cr18Ni9 be welded?
Yes — weldability is rated excellent (85/100). Very good with ER308/E308 (or 308L for repair of low-carbon heats); no preheat, keep interpass low, back-purge and pickle/passivate the weld area.
What surface finishes work on ZG1Cr18Ni9?
Shot blast and pickle (HNO₃-HF) then passivate; electropolishing gives best hygienic finish, plating and painting are rarely needed.
Can ZG1Cr18Ni9 be formed, bent or molded?
Sand, investment and centrifugal casting all suitable; allow ~2.0–2.3% shrinkage, use generous risers/chills because of long freezing range and hot-tearing tendency.
What is the maximum service temperature of ZG1Cr18Ni9?
ZG1Cr18Ni9 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 ZG1Cr18Ni9-ST and ZG1Cr18Ni9-F?
ST is the default condition — standard supply condition for pressure-retaining valve and pump castings; carbides dissolved for maximum corrosion resistance and ductility. F: cheapest condition for non-pressure, non-corrosive brackets and general hardware; interdendritic carbides reduce corrosion resistance and ductility. Yield strength is 250 MPa in ST versus 245 MPa in F.
How much does ZG1Cr18Ni9 cost?
ZG1Cr18Ni9 is a premium-cost stainless 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
- ASTM A351/A351M — Castings, Austenitic, for Pressure-Containing Parts (CF8) — ASTM International (2018)
- ASTM A743/A743M — Castings, Iron-Chromium-Nickel, Corrosion Resistant, General Application — ASTM International (2021)
- GB/T 2100 (ZG07Cr19Ni9) (2017)
- ASM Handbook Vol. 1: Properties and Selection — Cast Stainless Steels — ASM International (1990)
- High-Alloy Data Sheets, Corrosion Resistant Type (CF8) — Steel Founders' Society of America (2004)
- (ZG1Cr18Ni9/CF8 ) (2026)
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.