ASTM A204 Grade B is a molybdenum‑alloy pressure vessel steel plate designed for medium‑temperature service in boilers, heat‑exchanger shells, and petrochemical equipment. Compared with Grade A, A204 Gr.B provides higher strength and improved thermal stability, making it suitable for components exposed to sustained elevated temperatures. The grade offers dependable weldability, uniform mechanical behavior, and reliable performance in pressure‑bearing structures requiring moderate creep resistance and long‑term durability.

Chemical Composition

C	Mn	P	S	Si	Mo
≤0.28	0.40–0.90	≤0.025	≤ 0.025	0.15–0.40	0.45–0.60

 
Mechanical Properties

Property	Yield Strength	Tensile Strength	Elongation
Requirement	≥ 275 MPa	450-585MPa	≥ 20%

 
Dimensions

Thickness	3–150 mm
Width	1220–4200 mm
Length	5000–18000 mm
Supports custom cutting and shaping.

 

Stock & Processing

• Regular stock for A204 Grade B

• Cutting, drilling, welding, bending, machining

• Custom dimensions available

• Fast delivery for project orders

• Global supply capability

 Applications

• Medium‑temperature pressure vessels

• Boilers and heat‑exchanger shells

• Petrochemical reactors

• Industrial heating equipment

• Components requiring stable strength at elevated temperatures