SHEAR CRACKING REASON OF HOT ROLLED HIGH STRENGTH PLATE

The forming mechanism of shear cracking in HR plate with high strength was researched. The crack obviously differed from delamination which was derived from center-crack and segregation in slab. Intrinsic factors resulting in shear cracking were martensite band structure,biggish grains of TiN（C）dispersed in base structure and phosphor segregating near crystal border. Extrinsic factor resulting in shear cracking was improper cutting technics. Some effective measures were proposed to prevent the defect.