Steel grade Q390B is under steel specification GB/T1591 which is for high strength low alloy structural steels.When customers need special sizes for steel Q390B useage,Xinsteel has the ability to cut and weld in our processing plant for small parts,round plate,seal head and other frames.
GB/T1591 Q390 contains five different steel grades as Q390A,Q390B,Q390C,Q390D and Q390E.Structural steel Q390D shall be done impacting test at low temperature minus 20 degree centigrade.Normalised heat treatment suggested to be done for low alloy steel plate Q390D in heavy thickness.