Cause Analysis and Control of Transverse Cracks on the Surface of Beam Blank
Aiming at the current situation of transverse cracks on the surface of billet casting produced by a domestic steel plant during the production of Q355 grade and Q420 grade shaped billet low-alloy steel,the mechanism of transverse cracks at the flange tip of continuous casting billet and the corresponding relationship between the main influencing fac-tors have been analyzed,so as to reduce the incidence of transverse cracks on the beam blank.The results show that the cast billet surface transverse cracks along the coarse aus-tenite grain,the temperature range of Q355 grade steel low-plasticity zone is 600~620℃and 740~920℃,the temperature range of Q420 grade steel low-plasticity zone is 600~950℃.The process measures such as increasing the casting speed of the caster,reducing the intensity of cooling water,and reducing the aluminum content of the steel grade can ef-fectively control the generation of transverse cracks on the surface of the flange tip of beam blanks.