Steel A532 Class I Type A-HT (Hardened and tempered)
Heat-treated state
ASTM A532 Class I Type A
Specify when maximum abrasion resistance is required; austenitising plus temper transforms retained austenite to give ≥600 HB, at the cost of a further loss of already minimal toughness and a higher risk of quench cracks.
Values for the HT condition
Other A532 Class I Type A tempers and conditions
A532 Class I Type A is listed in 3 conditions; see the grade overview at A532 Class I Type A.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
HTThis page Hardened and tempered | Specify when maximum abrasion resistance is required; austenitising plus temper transforms retained austenite to give ≥600 HB, at the cost of a further loss of already minimal toughness and a higher risk of quench cracks. | — | 380 | 0 | 58 HRC | — |
ACDefault Spheroidize annealed | Standard commercial supply for mill liners and pump parts; martensite plus retained austenite formed on cooling in mould, no separate hardening cycle. | — | 400 | 0 | 55 HRC | 2 % IACS |
Stress relieved | Pick for thick or complex castings where residual casting stress causes cracking; hardness is essentially unchanged but toughness and dimensional stability improve slightly. | — | 420 | 0 | 54 HRC | 2 % IACS |
What is A532 Class I Type A-HT?
A532 Class I Type A-HT is A532 Class I Type A heat treated to HT — specify when maximum abrasion resistance is required; austenitising plus temper transforms retained austenite to give ≥600 HB, at the cost of a further loss of already minimal toughness and a higher risk of quench cracks. A532 Class I Type A-HT has a tensile strength of 380 MPa (55.1 ksi), weaker than 95% of steel grades. Elongation at break is 0% and the elastic modulus is 175 GPa (25.4 Msi). A532 Class I Type A-HT has a density of 7.65 g/cm³ (0.276 lb/in³), lighter than 97% of steel grades. It melts at 1,150°C (2,102 °F). AC is the default condition FabDigit quotes; HT is available on request or by drawing note.
Advantages
- Good corrosion resistance — 22/100, better than 90% of steel grades
Limitations
- Limited ductility — 0%, worse than 100% of steel grades
- Difficult to machine — 2/100, worse than 100% of steel grades
- Difficult to weld — 5/100, worse than 100% of steel grades
- Limited formability — 0/100, worse than 100% of steel grades
- Low electrical conductivity — 2 % IACS, worse than 99% of steel grades
A532 Class I Type A-HT properties
Typical room-temperature values for A532 Class I Type A-HT; 10 are specific to this condition. Other listed values are A532 Class I Type A reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
A532 Class I Type A-HT has a density of 7.65 g/cm³ (0.276 lb/in³), lighter than 97% of steel grades. It melts at 1,150°C (2,102 °F).
Mechanical14
A532 Class I Type A-HT has a tensile strength of 380 MPa (55.1 ksi), weaker than 95% of steel grades. Elongation at break is 0% and the elastic modulus is 175 GPa (25.4 Msi).
Thermal6
A532 Class I Type A-HT is rated for continuous service to 250°C (482 °F). It conducts heat at 22 W/m·K (12.7 BTU/hr·ft·°F), worse than 93% of steel grades. Thermal expansion is 12.5 µm/m·K (6.94 µin/in·°F).
Electrical3
A532 Class I Type A-HT conducts electricity at 2 % IACS, worse than 99% of steel grades.
Chemical & Environmental2
Corrosion resistance is poor (22/100), better than 90% of steel grades.
Sustainability4
Producing a kilogram of A532 Class I Type A-HT takes about 26 MJ of energy and emits 2.2 kg of CO₂ — less than 64% of steel grades. Typical recycled content is 75%.
Manufacturability7
A532 Class I Type A-HT's machinability is not recommended (2/100, worse than 100% of steel grades); weldability not recommended (5/100); formability not recommended (0/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with A532 Class I Type A-HT
Is A532 Class I Type A easy to machine?
Not machinable with carbide tooling — finish by wet grinding, CBN wheels or EDM; cast all holes and profiles to near net shape.
Can A532 Class I Type A be welded?
Effectively unweldable structurally; only local repair with high-Ni or austenitic stainless electrodes at 300–400 °C preheat with slow cooling.
Can A532 Class I Type A be formed, bent or molded?
Sand or chill-mould casting only; use generous fillets, chills for section control and very slow shakeout to avoid hot tears and quench cracks.
What surface finishes work on A532 Class I Type A?
Normally supplied as-cast and shot-blasted; ground faces where sealing is required, no plating or anodizing — protect idle parts with oil or paint against rusting.
A532 Class I Type A 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 |
|---|---|---|
| Ctotal carbon | 2.8 – 3.6 | 3.2 |
| Mn | ≤ 2 | 0.6 |
| Si | ≤ 0.8 | 0.5 |
| Nisuppresses pearlite, promotes martensite | 3.3 – 5 | 4 |
| Cr | 1.4 – 4 | 2 |
| Mooptional, for heavy sections | ≤ 1 | 0.3 |
| P | ≤ 0.3 | — |
| S | ≤ 0.15 | — |
| Fe | balance | — |
A532 Class I Type A-HT — frequently asked
What is A532 Class I Type A-HT used for?
A532 Class I Type A-HT is typically used for pump liners, grinding balls, crusher wear plates and slurry impellers. In short: extreme abrasion resistance; 55 HRC as-cast; cast to net shape only.
What is the tensile strength of A532 Class I Type A-HT?
A532 Class I Type A-HT has a typical tensile strength of 380 MPa (55.1 ksi) — weaker than 95% of steel grades. Strength varies by condition: see the 3 listed tempers.
Is A532 Class I Type A-HT easy to machine?
Not especially — machinability is rated not recommended (2/100, worse than 100% of steel grades). Not machinable with carbide tooling — finish by wet grinding, CBN wheels or EDM; cast all holes and profiles to near net shape.
Can A532 Class I Type A-HT be welded?
Not readily — weldability is rated not recommended (5/100). Effectively unweldable structurally; only local repair with high-Ni or austenitic stainless electrodes at 300–400 °C preheat with slow cooling.
What surface finishes work on A532 Class I Type A-HT?
Normally supplied as-cast and shot-blasted; ground faces where sealing is required, no plating or anodizing — protect idle parts with oil or paint against rusting.
Can A532 Class I Type A-HT be formed, bent or molded?
Sand or chill-mould casting only; use generous fillets, chills for section control and very slow shakeout to avoid hot tears and quench cracks.
What is the maximum service temperature of A532 Class I Type A-HT?
A532 Class I Type A-HT is rated for continuous use to about 250°C (482 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- ASTM A532/A532M — Abrasion-Resistant Cast Irons — ASTM International (2021)
- EN 12513 — Founding: Abrasion resistant cast irons — CEN (2011)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels and High-Performance Alloys (Abrasion-Resistant Cast Irons) — ASM International (1990)
- ASM Handbook Vol. 15 — Casting — ASM International (2008)
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.