What is the ASTM A537 steel standard?

ASTM A537 standard steel is used for fusion-welded pressure vessels and heat-treated carbon-manganese-silicon steel plates for structural use. The supplied steel plates have the following three classes: A537CL1, A537CL2, A537CL3.
ASTM A537 steel plates furnished under this specification have different tensile requirements in the following.  

Class	Heat  Treatment	Thickness	Yield Strength,  min, ksi [MPa]	Tensile Strength,  min, ksi [MPa]
A537 Class 1	Normalized	21/2 in. and under [65 mm and under]	50  [345]	70  [485]
		Over 21/2 in.  [Over 65 mm]	45  [310]	65  [450]
A537 Class 2	Quenched and tempered	21/2 in. and under [65 mm and under]	60  [415]	80  [550]
		Over 21/2 to 4 in.  [Over 65 to 100 mm]	55  [380]	75  [515]
		Over 4 in.  [Over 100 mm]	46  [315]	70  [485]
A537 Class 3	Quenched and tempered	21/2 in. and under [65 mm and under]	55  [380]	80  [550]
		Over 21/2 to 4 in.  [Over 65 to 100 mm]	50  [345]	75  [515]
		Over 4 in.  [Over 100 mm]	40  [275]	70  [485]

A537CL1, A537CL2, A537CL3 steel typical applications include pressure vessels designed for moderate and lower temperature service requiring excellent notch toughness as well as API storage tanks.
 

Pre: Q345B tower steel

Next: The differences between SA516Gr70 steel and Q345R steel