Q345B steel vs Q355B steel

Q355B is a new type of Q345B steel under GB/T1591-2018 low alloy structural steel standard. It is equivalent to Q345B in GB/T1591-2008 version and S355JR in EN 10025-2:2004 version.

Chemical composition(%) comparison of Q345B and Q355B:

Material	C max.	Si max.	Mn max.	P max.	S max.	Cr max.	Ni max.	Cu max.	N max.	Nb max.	V max.	Ti max.	Mo max.
Q345B	0.20	0.50	1.70	0.035	0.035	0.30	0.50	0.30	0.012	0.07	0.15	0.20	0.10
Q355B	0.20	0.55	1.60	0.030	0.030	0.30	0.30	0.40	0.012	-	-	-	-

Mechanical properties comparison of Q345B and Q355B steel:

Grade	Yield strength MPa in different thickness mm
Grade	≤16	16-40	40-63	63-80	80-100	100-150	150-200	200-250	250-400
Q345B	≥345	≥335	≥325	≥315	≥305	≥285	≥275	≥265	-
Q355B	≥355	≥345	≥335	≥325	≥315	≥295	≥285	≥275	-

Grade	Tensile strength MPa in different thickness mm
Grade	≤40	40-63	63-80	80-100	100-150	150-250	250-400
Q345B	470-630	470-630	470-630	470-630	450-600	450-600	-
Q355B	470-630	470-630	470-630	470-630	450-600	450-600	-

BBN steel can supply both low alloy steel Q345B and Q355B steel plates with further processing service. Welcome to send us inquiry if you are interested in Q345B plate price.

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