Cause Analysis of Roller Cracking of 600 MPa Grade Automobile Beam Steel
This article describes the causes of surface cracking at the roll bending of automo-bile beam steel during slitting and roll forming.After metallurgical microscopy,scanning electron microscopy and other testing and analysis,it is found that there are more D-type oxides and protec-tion of slag composition of foreign inclusions exists in the cracked parts of the fracture,which dis-rupt the continuity of the substrate,leading to the concentration of stress during the deformation of the material.In roll forming process,inclusions in the matrix produces a source of cracks,with the increase in deformation crack expansion,resulting in steel plate forming surface cracking.