The higher steel grade NK Grade FH40 shipbuilding steel plate are used abnormally owning to its high cost and substitutability.With the minimum yield point at 390 Mpa,and tensile strength within 510-650 Mpa,steel plate NK Grade FH40 can bear the higher strength and used to some steel structure parts in ships.At current,Xinsteel is cooperating with Wuyang steel mill about starting rolling the heavy shipbuilding steel plate NK Grade FH40 with the unit weight about 30 tons.This rolling should be from steel ingots and normally the plate rolling yield should be above 72 percentage.