SA204 Grade B steel plate is one kind Molybdenum alloy steels in ASME SA204/SA204M specification, and SA302 Grade B steel plate is one kind Manganese-Molybdenum alloy steels in ASME SA302/SA302M specification.These two steel grades are both for boiler and pressure vessel building usage.SA302 Grade B steel plate requires a higher Mn% in chemical composition than SA204 Grade B steel plate,for Mo% alloy steel elements,they are the same as 0.45-0.6%.SA302 Grade B steel plate owned a higher yield strength (Min.345 Mpa) and tensile strength (550-690 Mpa) than SA204 Grade B steel plate.

For heat treatment,SA204 Grade B steel plate have to be done Normalized treatment for plate thickness over 40mm,however SA302 Grade B steel plate requires Normalized treatment for thickness over 50mm.Actually we supplying SA204 Grade B steel plate and SA302 Grade B steel plate with Normalized heat treatment even for thickness range 5-40mm for guarantee good property.