Stainless Steel CF8A SA-HIP
Heat-treated state
ASTM CF8A · UNS J92600
SA-HIP = hot isostatically pressed then solution annealed
Use where internal microporosity must be eliminated for fatigue-critical or high-integrity radiographed castings.
Values for the SA-HIP condition
Other CF8A tempers and conditions
CF8A is listed in 4 conditions; see the grade overview at CF8A.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Spheroidize annealed | Only for non-pressure, non-corrosive structural parts; carbides at grain boundaries make it unacceptable for ASTM A351 service. | 260 | 500 | 30 | 170 HB | 2.4 % IACS |
SADefault Solution annealed (≥1040 °C, water quenched), static sand/investment… | Standard supply condition for all ASTM A351 CF8A pressure castings; maximum corrosion resistance and toughness. | 275 | 550 | 50 | 155 HB | — |
SA-HIPThis page Hot isostatically pressed then solution annealed | Use where internal microporosity must be eliminated for fatigue-critical or high-integrity radiographed castings. | 285 | 570 | 55 | 155 HB | 2.4 % IACS |
Centrifugally cast tube/ring, solution annealed | Choose for cylindrical pressure parts (pipe, valve liners) where centrifugal soundness raises strength and lowers porosity. | 300 | 585 | 45 | 160 HB | 2.4 % IACS |
What is CF8A SA-HIP?
CF8A SA-HIP is CF8A heat treated to SA-HIP — use where internal microporosity must be eliminated for fatigue-critical or high-integrity radiographed castings. CF8A SA-HIP has a yield strength of 285 MPa (41.3 ksi) and a tensile strength of 570 MPa (82.7 ksi) — weaker than 74% of stainless steel grades. Elongation at break is 55% and the elastic modulus is 197 GPa (28.6 Msi). CF8A SA-HIP 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-HIP is available on request or by drawing note.
Advantages
- Ductile — tolerates forming and impact — 55%, better than 97% of stainless steel grades
- Tough — resists crack growth — 220 MPa·√m (200.2 ksi·√in), better than 97% of stainless steel grades
- Readily welded — 82/100, better than 84% of stainless steel grades
Limitations
- Limited formability — 18/100, worse than 89% of stainless steel grades
- Hard to polish — 60/100, worse than 80% of stainless steel grades
CF8A SA-HIP properties
Typical room-temperature values for CF8A SA-HIP; 22 are specific to this condition. Other listed values are CF8A reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
CF8A SA-HIP 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
CF8A SA-HIP has a yield strength of 285 MPa (41.3 ksi) and a tensile strength of 570 MPa (82.7 ksi) — weaker than 74% of stainless steel grades. Elongation at break is 55% and the elastic modulus is 197 GPa (28.6 Msi).
Thermal6
CF8A SA-HIP is rated for continuous service to 650°C (1,202 °F). It conducts heat at 16.3 W/m·K (9.42 BTU/hr·ft·°F), better than 68% of stainless steel grades. Thermal expansion is 17 µm/m·K (9.44 µin/in·°F).
Electrical3
CF8A SA-HIP conducts electricity at 2.4 % IACS, better than 67% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is very good (71/100), better than 70% of stainless steel grades.
Sustainability4
Producing a kilogram of CF8A SA-HIP takes about 53 MJ of energy and emits 4.5 kg of CO₂ — less than 67% of stainless steel grades. Typical recycled content is 80%.
Manufacturability8
CF8A SA-HIP's machinability is fair (42/100, better than 79% of stainless steel grades); weldability very good (82/100); formability poor (18/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with CF8A SA-HIP
Is CF8A easy to machine?
Machine like 304: rigid setups, sharp positive-rake carbide, heavy positive feed to cut under the work-hardened skin, flood coolant, and expect abrasive casting scale on the first pass.
Can CF8A be welded?
Excellent weldability with GTAW/SMAW using E308/ER308 (or 308L for corrosive duty); the 5–20 % ferrite suppresses hot cracking, no preheat needed, keep interpass below ~150 °C.
Can CF8A be formed, bent or molded?
Sand or investment cast with generous risering — long freezing range and 2.2 % solidification shrinkage require good gating; solution anneal ≥1040 °C with water quench after casting/repair welding.
What surface finishes work on CF8A?
Passivate per ASTM A967 (nitric or citric) after machining; shot blast plus pickling removes casting scale, and electropolishing gives sanitary finishes though porosity limits mirror polish.
CF8A 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 | ≤ 0.08 | 0.06 |
| Mn | ≤ 1.5 | 1 |
| Si | ≤ 2 | 1.3 |
| P | ≤ 0.04 | 0.03 |
| S | ≤ 0.04 | 0.02 |
| Cr | 18 – 21 | 19.5 |
| Nibalanced toward the low side to raise ferrite and meet the higher CF8A strength | 8 – 11 | 9 |
| Moresidual, per A351 supplementary limits | ≤ 0.5 | 0.2 |
| Fe | balance | — |
CF8A SA-HIP — frequently asked
What is CF8A SA-HIP used for?
CF8A SA-HIP is typically used for valve bodies, pump housings, pressure vessel fittings and general chemical service castings. In short: high-strength CF8 variant; 650 °C service capability; standard 19Cr-9Ni casting.
What is the yield strength of CF8A SA-HIP?
CF8A SA-HIP has a typical yield strength of 285 MPa (41.3 ksi) and a tensile strength of 570 MPa (82.7 ksi) — weaker than 74% of stainless steel grades. Strength varies by condition: see the 4 listed tempers.
Is CF8A SA-HIP easy to machine?
Not especially — machinability is rated fair (42/100, better than 79% of stainless steel grades). Machine like 304: rigid setups, sharp positive-rake carbide, heavy positive feed to cut under the work-hardened skin, flood coolant, and expect abrasive casting scale on the first pass.
Can CF8A SA-HIP be welded?
Yes — weldability is rated very good (82/100). Excellent weldability with GTAW/SMAW using E308/ER308 (or 308L for corrosive duty); the 5–20 % ferrite suppresses hot cracking, no preheat needed, keep interpass below ~150 °C.
What surface finishes work on CF8A SA-HIP?
Passivate per ASTM A967 (nitric or citric) after machining; shot blast plus pickling removes casting scale, and electropolishing gives sanitary finishes though porosity limits mirror polish.
Can CF8A SA-HIP be formed, bent or molded?
Sand or investment cast with generous risering — long freezing range and 2.2 % solidification shrinkage require good gating; solution anneal ≥1040 °C with water quench after casting/repair welding.
What is the maximum service temperature of CF8A SA-HIP?
CF8A SA-HIP is rated for continuous use to about 650°C (1,202 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between CF8A-SA and CF8A SA-CENT?
SA is the default condition — standard supply condition for all ASTM A351 CF8A pressure castings; maximum corrosion resistance and toughness. SA-CENT: choose for cylindrical pressure parts (pipe, valve liners) where centrifugal soundness raises strength and lowers porosity. Yield strength is 275 MPa in SA versus 300 MPa in SA-CENT.
Sources
- ASTM A351/A351M — Castings, Austenitic, for Pressure-Containing Parts — ASTM International (2018)
- ASTM A451/A451M — Centrifugally Cast Austenitic Steel Pipe for High-Temperature Service — ASTM International (2021)
- 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 / ASM (1995)
- GB/T 12230 (ZG07Cr19Ni9) — SAC (2016)
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.