What is GB T1591 Q345B steel equivalent ASTM

GB T1591 Q345B steel is Chinese low alloy high strength steel. The low alloy high strength steel has wide application in the world. In ASTM standard, there is also low alloy high strength steel, and the most widely used among them is ASTM A572 Gr 50 steel, which is GB T1591 Q345B steel equivalent ASTM material.

The equivalent of GB T1591 Q345B steel and ASTM A572 Gr 50 steel are mainly expressed in similarity of chemical composition and mechanical properties.

Chemical composition of GB T1591 Q345B steel and ASTM A572 Gr 50 steel:

Grade

C (t≤16mm)

Q345B

0.20 max

0.50 max

1.70 max

0.035 max

0.07 max

0.15 max

0.20 max

0.30 max

0.50 max

0.30 max

0.012 max

0.1max

A572 Gr 50

0.26 max

0.40 max

1.65 max

0.040 max

0.050 max

Mechanical properties of ASTM A572 Gr 50 equivalent material:

Grade	Yield strength ReH/(N/mm2)	Tensile strength Rm/(N/mm2)	Elongation A/%	Charpy V test
Grade	(t≤16mm) min	(3mm≤t≤16mm)	(3mm≤t≤40mm) min	Temperature/℃	Impact energy (Longitudinal)/J min
Q345B	345	470-630	20	20	34
A572 Gr 50	345	450	18	-	-

BBN steel supplies GB T1591 Q345B steel equivalent ASTM A572 Gr 50 steel and other foreign standard low alloy high strength steel as well. Other than standard size GB T1591 Q345B steel and ASTM A572 Gr 50 steel plates etc. Products, BBN steel also provide non-standard size steel materials though cutting, bending, welding and so on deep processing.