ASTM A532 Class II Type A 12% Cr
on January 7, 2026
Exploring ASTM A532 Class 2 Type A
ASTM A532 Class II Type A 12% Cr is an alloy that has improved toughness compared to the Ni-Hard alloys. It has an average carbide percentage of 22%. Its matrix is comprised of martensite when in the hardened condition. The carbides are of the M7C3 variety, with some secondary carbides thanks to the addition of molybdenum. A hardness of >650 BHN can be achieved with the proper heat treatment.
More cost-effective than Ni-Hard, and with good wear resistance, it can be used in a controlled, dry wear application when there is little concern of corrosion.
Read: To understand why chrome white iron is so abrasion resistant, read this.
Composition of ASTM A532 Class 2 Type A
| C | Mn | Si | Cr | Mo | |
|---|---|---|---|---|---|
| Min% | 2.0 | 0 | 0 | 11 | 0.5 |
| Max% | 3.3 | 1.0 | 1.5 | 14 | 3.0 |
Physical and Mechanical Properties of ASTM A532 Class 2 Type A
| Density lb/in³ (g/cm³) | 0.28 (7.7) |
| Thermal Conductivity Btu/hr·ft·°F (W/m·K) | 8.6-17.3 (15-30) |
| Specific Heat at 70°F Btu/lb·°F (J/Kg·k) | 0.119 |
| Coefficient of Thermal Expansion Ɛ/°F (Ɛ/°C) X10⁶ average between 70-1112°F | 7.2 (13) |
| Melting Temperature (°F) | 2300F |
| Compressive Strength Ksi (MPa) | 429 (2960) |
| Transverse Strength Ksi (MPa) | 136 (938) |
Typical Hardness of ASTM A532 Class 2 Type A
| Brinell (depends on thickness) | |
|---|---|
| As-Cast | 450-550 |
| Annealed | 350-450 |
| Hardened | 600-650 |
Designing With ASTM A532 Class 2 Type A
ASTM A532 Class 2 Type A fills a niche similar to the ASTM A532 Class I alloys, but with improved toughness and corrosion resistance.
It can be supplied in the as-cast condition at 550 BHN, or the hardened condition at 650 BHN. This alloy is chill-cast for some applications and will achieve a hardness of 550 BHN in this condition. Specialized heat treatments will achieve the desired through-hardness in the casting.
ASTM A532 Class II Type A has improved toughness compared to the Class I alloys, but it is still considered a brittle material. Work closely with your foundry during the design phase to determine optimal section thickness for the required properties.
The ASTM A532 Class II Type A material can be softened for machining if required. If softened for machining, it can be reduced to a hardness of 400BHN.
Read: To learn more about designing with chrome white iron read, “The Top 5 Design Mistakes in Chrome White Iron Castings”.
Corrosion Properties of ASTM A532 Class 2 Type A
The 12% Cr alloy has improved corrosion resistance compared to the ASTM A532 Class I alloys. If the corrosion environment is extreme and abrasive, consider the using the 28-30% Cr alloy.
Applications for ASTM A532 Class 2 Type A
The 12% Cr alloy would be best suited for a controlled, dry wear application. It would be a good replacement for any Ni-Hard alloy, offering an increased toughness.
- Standard wall and chute liners
- Mixed cement
- Mill liners and lip liners
- Small wear pumps and impellers
- Sustainability and recycling industry wear parts like paddles and blades
Read: To learn more about chrome white iron and to see other ASTM A532 data sheets, check out our chrome white iron webpage.
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