The causes and preventive measures of tensile crack of DNV GL DH32 shipbuilding plate are as follows:
(1) High content and low melting point elements in DNV GL DH32 shipbuilding plate directly lead to tensile cracks.
At present, if it can not be eliminated in steelmaking process, the content of low melting point elements in DNV GL DH32 shipbuilding plate in hot metal should be reduced as far as possible.
(2) In order to avoid the influence of Cu, appropriate amount of Ni can be added into DNV GL DH32 shipbuilding plate if necessary. At present, the production of our company is controlled between 0.010% and 0.025%.
(3) The content of P and S in DNV GL DH32 shipbuilding plate should be as low as possible, and the content of Nb should also be reasonably controlled at 0.010% ~ 0.020%.
(4) The preheating temperature of DNV GL DH32 shipbuilding plate should be as high as possible and the residence time of billet should be shortened.
Strictly speaking, the tensile crack of DNV GL DH32 shipbuilding plate is not absolutely eliminated, we just found the important factors affecting its production and carried out certain control.
