Steel A202-GrB
Grade
ASTM A202
GrB = grade B
Pick when higher allowable stress (585–725 MPa tensile) is needed and the extra carbon's preheat/PWHT demands are acceptable.
Values for the GrB condition
Other A202 tempers and conditions
A202 is listed in 2 conditions; see the grade overview at A202.
- GrA
- GrB
Compare all 2 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
GrADefault Grade A | Pick when 515–655 MPa tensile with the best weldability and toughness of the two levels is wanted; supplied as-rolled or normalized. | 350 | 570 | 24 | 163 HB | 40 W/m·K |
GrBThis page Grade B | Pick when higher allowable stress (585–725 MPa tensile) is needed and the extra carbon's preheat/PWHT demands are acceptable. | 390 | 640 | 21 | 187 HB | 39 W/m·K |
What is A202-GrB?
A202-GrB is A202 in the GrB grade — pick when higher allowable stress (585–725 MPa tensile) is needed and the extra carbon's preheat/PWHT demands are acceptable. A202-GrB has a yield strength of 390 MPa (56.6 ksi) and a tensile strength of 640 MPa (92.8 ksi) — weaker than 64% of steel grades. Elongation at break is 21% and the elastic modulus is 203 GPa (29.4 Msi). A202-GrB has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F). GrA is the default condition FabDigit quotes; GrB is available on request or by drawing note.
Advantages
- High service temperature — 450°C (842 °F), better than 86% of steel grades
A202-GrB properties
Typical room-temperature values for A202-GrB; 34 are specific to this condition. Other listed values are A202 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
A202-GrB has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical16
A202-GrB has a yield strength of 390 MPa (56.6 ksi) and a tensile strength of 640 MPa (92.8 ksi) — weaker than 64% of steel grades. Elongation at break is 21% and the elastic modulus is 203 GPa (29.4 Msi).
Thermal6
A202-GrB is rated for continuous service to 450°C (842 °F). It conducts heat at 39 W/m·K (22.5 BTU/hr·ft·°F), worse than 67% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
A202-GrB conducts electricity at 7.5 % IACS, worse than 67% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (15/100), better than 75% of steel grades.
Sustainability4
Producing a kilogram of A202-GrB takes about 26 MJ of energy and emits 2 kg of CO₂ — less than 64% of steel grades. Typical recycled content is 30%.
Manufacturability7
A202-GrB's machinability is fair (52/100, better than 52% of steel grades); weldability good (55/100); formability fair (52/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with A202-GrB
Is A202 easy to machine?
Machines like a 190 HB low-alloy plate — carbide tooling, moderate speeds; the ~0.75 % Si makes chips gummier than plain carbon steel.
Can A202 be welded?
Weldable with low-hydrogen SMAW/SAW consumables but preheat 100–200 °C and PWHT at 595–650 °C are normally specified, especially for Grade B and thick sections.
Can A202 be formed, bent or molded?
Cold-roll shells with generous bend radii; hot forming 900–1000 °C followed by re-normalizing is preferred for heads and heavy plate.
What surface finishes work on A202?
No inherent corrosion resistance — blast to Sa 2.5 and apply epoxy/inorganic-zinc coating, weld-overlay or clad for wet service.
A202 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 |
|---|---|---|
| CGrade A; Grade B up to 0.25 % (heavier plate limits per A202) | ≤ 0.17 | 0.15 |
| Mn | 1.05 – 1.4 | 1.2 |
| Sisolid-solution strengthener, raises weld hardenability | 0.6 – 0.9 | 0.75 |
| Cr | 0.35 – 0.6 | 0.48 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.04 | 0.01 |
| Fe | balance | — |
A202-GrB — frequently asked
What is A202-GrB used for?
A202-GrB is typically used for pressure vessel shells, boiler drums and storage tank plates for higher-strength service. In short: legacy Cr-Mn-Si vessel plate; stronger than carbon plate; superseded by A387 grades.
What is the yield strength of A202-GrB?
A202-GrB has a typical yield strength of 390 MPa (56.6 ksi) and a tensile strength of 640 MPa (92.8 ksi) — weaker than 64% of steel grades. Strength varies by condition: see the 2 listed tempers.
Is A202-GrB easy to machine?
Reasonably — machinability is rated fair (52/100, better than 52% of steel grades). Machines like a 190 HB low-alloy plate — carbide tooling, moderate speeds; the ~0.75 % Si makes chips gummier than plain carbon steel.
Can A202-GrB be welded?
Yes — weldability is rated good (55/100). Weldable with low-hydrogen SMAW/SAW consumables but preheat 100–200 °C and PWHT at 595–650 °C are normally specified, especially for Grade B and thick sections.
What surface finishes work on A202-GrB?
No inherent corrosion resistance — blast to Sa 2.5 and apply epoxy/inorganic-zinc coating, weld-overlay or clad for wet service.
Can A202-GrB be formed, bent or molded?
Cold-roll shells with generous bend radii; hot forming 900–1000 °C followed by re-normalizing is preferred for heads and heavy plate.
What is the maximum service temperature of A202-GrB?
A202-GrB is rated for continuous use to about 450°C (842 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between A202-GrA and A202-GrB?
GrA is the default condition — pick when 515–655 MPa tensile with the best weldability and toughness of the two levels is wanted; supplied as-rolled or normalized. GrB: pick when higher allowable stress (585–725 MPa tensile) is needed and the extra carbon's preheat/PWHT demands are acceptable. Yield strength is 350 MPa in GrA versus 390 MPa in GrB.
Sources
- ASTM A202/A202M — Pressure Vessel Plates, Alloy Steel, Chromium-Manganese-Silicon — ASTM International (2019)
- ASTM A20/A20M — General Requirements for Steel Plates for Pressure Vessels — ASTM International (2020)
- ASME BPVC Section II Part D — Materials, Properties — ASME (2023)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.19 — Fatigue and Fracture — ASM International (1996)
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.