Stainless Steel CA15
ASTM CA15 · UNS J91150
CA15 is the basic 12% Cr cast martensitic stainless steel (UNS J91150, ASTM A743 Gr.
Reference datasheet — CA15 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 NT650 condition
CA15 tempers and conditions
CA15 is supplied in 6 conditions, soft to hard. NT650 is the default FabDigit quotes; the values on this page are for it.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Softest condition for heavy machining or before final hardening; not a normal delivery condition for pressure parts. | 415 | 655 | 26 | 180 HB | — |
NT650Default N&T | Default commercial condition for pump/valve castings: best combination of toughness, corrosion resistance and code compliance. | 510 | 700 | 22 | 20 HRC | — |
Spheroidize annealed | Rough/blank castings shipped before heat treatment; properties highly variable and not code-acceptable. | 620 | 800 | 8 | 31 HRC | 2.9 % IACS |
Q&T | Choose when higher strength than the standard N&T condition is needed with acceptable toughness (impellers, wear rings). | 690 | 830 | 18 | 26 HRC | — |
Q&T | Maximum strength/wear resistance for non-corrosive, non-impact duty; toughness and corrosion resistance are reduced. | 900 | 1,100 | 11 | 37 HRC | — |
Hardened | Intermediate state only — maximum hardness but brittle and crack-prone; must be tempered before service. | 1,100 | 1,450 | 4 | 46 HRC | 2.8 % IACS |
What is CA15?
CA15 is the basic 12% Cr cast martensitic stainless steel (UNS J91150, ASTM A743 Gr. CA15, 1.4011, GX12Cr12), hardenable by austenitizing and tempering to about 510 MPa yield, 700 MPa tensile, 22% elongation and 225 HB (20 HRC). It is the workhorse choice for sand and investment cast pump and valve bodies that need moderate corrosion resistance together with strength and wear resistance, with a maximum service temperature of 650 °C. Corrosion resistance is limited (score 45) and welding needs preheat plus a post-weld temper; CA6NM or CA6N are the nearest alternatives when higher toughness and easier weld repair are required. CA15 has a density of 7.61 g/cm³ (0.275 lb/in³), lighter than 96% of stainless steel grades. It melts at 1,480°C (2,696 °F). CA15 has a yield strength of 510 MPa (74 ksi) and a tensile strength of 700 MPa (102 ksi) — stronger than 78% of stainless steel grades. Elongation at break is 22% and the elastic modulus is 200 GPa (29 Msi).
What is CA15 used for?
- Pump casings
- Valve bodies and trim
- Compressor parts
- Turbine components
Advantages
- High electrical conductivity — 3 % IACS, better than 95% of stainless steel grades
- Conducts heat well — 24.5 W/m·K (14.2 BTU/hr·ft·°F), better than 85% of stainless steel grades
- Easy to machine — 45/100, better than 84% of stainless steel grades
- Low embodied carbon — 3.6 kg CO₂/kg, better than 83% of stainless steel grades
- High strength — 510 MPa (74 ksi), better than 78% of stainless steel grades
Limitations
- Limited formability — 10/100, worse than 95% of stainless steel grades
- Needs corrosion protection — 45/100, worse than 85% of stainless steel grades
- Difficult to weld — 40/100, worse than 83% of stainless steel grades
- Low fracture toughness — 85 MPa·√m (77.4 ksi·√in), worse than 77% of stainless steel grades
- Limited ductility — 22%, worse than 75% of stainless steel grades
CA15 properties
Typical room-temperature values for CA15-NT650; bars are the position among stainless steel grades.
Physical3
CA15 has a density of 7.61 g/cm³ (0.275 lb/in³), lighter than 96% of stainless steel grades. It melts at 1,480°C (2,696 °F).
Mechanical15
CA15 has a yield strength of 510 MPa (74 ksi) and a tensile strength of 700 MPa (102 ksi) — stronger than 78% of stainless steel grades. Elongation at break is 22% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
CA15 is rated for continuous service to 650°C (1,202 °F). It conducts heat at 24.5 W/m·K (14.2 BTU/hr·ft·°F), better than 85% of stainless steel grades. Thermal expansion is 10.3 µm/m·K (5.72 µin/in·°F).
Electrical3
CA15 conducts electricity at 3 % IACS, better than 95% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is fair (45/100), worse than 85% of stainless steel grades.
Sustainability4
Producing a kilogram of CA15 takes about 40 MJ of energy and emits 3.6 kg of CO₂ — less than 97% of stainless steel grades. Typical recycled content is 75%.
Manufacturability8
CA15's machinability is fair (45/100, better than 84% of stainless steel grades); weldability fair (40/100); formability not recommended (10/100).
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. CA15 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with CA15
Is CA15 easy to machine?
Machine in the annealed or high-tempered condition with rigid setups, sharp carbide tools, positive rake and generous coolant; work-hardens and gums less than austenitic grades but abrades tooling above ~30 HRC.
Can CA15 be welded?
Weldable with matching 410/E410 or austenitic 309/309L filler; preheat 200–315 °C, keep interpass warm, and post-weld temper at 620–760 °C to avoid hard, crack-prone HAZ martensite.
Can CA15 be formed, bent or molded?
Sand or investment cast; needs good risering (solidification shrinkage ~4 %), slow cooling from pouring, and mandatory austenitize+temper cycle to remove as-cast brittleness.
CA15 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 |
|---|---|---|
| C0.15 % max per ASTM A743/A217 | ≤ 0.15 | 0.12 |
| Mn | ≤ 1 | 0.6 |
| Si1.00 % max in ASTM A217 | ≤ 1.5 | 0.8 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.04 | 0.02 |
| Cr | 11.5 – 14 | 12.5 |
| Ni | ≤ 1 | 0.5 |
| MoMo may be present from scrap; capped at 0.50 % | ≤ 0.5 | 0.3 |
| Fe | balance |
What surface finishes work on CA15?
Passivate per ASTM A967 after machining; hard chrome, electroless nickel or nitriding improve wear; avoid tempering in 400–550 °C which embrittles and lowers corrosion resistance.
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 CA15 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- J91150
- ASTM
- A743 Gr. CA15
- Also called
- ZG1Cr13
- Similar grades
- SCS11.4011GX12Cr12
How much does CA15 cost?
CA15 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.
CA15 — frequently asked
What is CA15 used for?
CA15 is typically used for pump casings, valve bodies and trim, compressor parts and turbine components. In short: baseline 12Cr cast martensitic; heat-treatable pump/valve grade; moderate corrosion resistance.
What is the yield strength of CA15?
CA15 has a typical yield strength of 510 MPa (74 ksi) and a tensile strength of 700 MPa (102 ksi) — stronger than 78% of stainless steel grades. Strength varies by condition: see the 6 listed tempers.
Is CA15 easy to machine?
Reasonably — machinability is rated fair (45/100, better than 84% of stainless steel grades). Machine in the annealed or high-tempered condition with rigid setups, sharp carbide tools, positive rake and generous coolant; work-hardens and gums less than austenitic grades but abrades tooling above ~30 HRC.
Can CA15 be welded?
With care — weldability is rated fair (40/100). Weldable with matching 410/E410 or austenitic 309/309L filler; preheat 200–315 °C, keep interpass warm, and post-weld temper at 620–760 °C to avoid hard, crack-prone HAZ martensite.
What surface finishes work on CA15?
Passivate per ASTM A967 after machining; hard chrome, electroless nickel or nitriding improve wear; avoid tempering in 400–550 °C which embrittles and lowers corrosion resistance.
Can CA15 be formed, bent or molded?
Sand or investment cast; needs good risering (solidification shrinkage ~4 %), slow cooling from pouring, and mandatory austenitize+temper cycle to remove as-cast brittleness.
What is the maximum service temperature of CA15?
CA15 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 CA15-NT650 and CA15-H?
NT650 is the default condition — default commercial condition for pump/valve castings: best combination of toughness, corrosion resistance and code compliance. H: intermediate state only — maximum hardness but brittle and crack-prone; must be tempered before service. Yield strength is 510 MPa in NT650 versus 1,100 MPa in H.
How much does CA15 cost?
CA15 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 A743/A743M — Castings, Iron-Chromium, Iron-Chromium-Nickel, Corrosion Resistant, for General Application (Gr. CA15) — ASTM International (2019)
- ASTM A217/A217M — Steel Castings, Martensitic Stainless and Alloy, for Pressure-Containing Parts (Gr. CA15) — ASTM International (2021)
- ASTM A487/A487M — Steel Castings Suitable for Pressure Service — ASTM International (2020)
- Steel Castings Handbook, Supplement 8: High Alloy Data Sheets Corrosion Series — Steel Founders' Society of America (2004)
- ASM Handbook Vol. 1: Properties and Selection — Irons, Steels, and High-Performance Alloys — ASM International (1990)
- GB/T 2100 / GB/T 6967 — (ZG12Cr13 ) — SAC (2017)
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.