철강의 열연공정에서 기공의 치밀화와 접합강도의 유한요소해석

Abstract

The closing and welding behavior of internal pores in the center of steel slabs during hot rolling was studied using the finite element method (FEM). Pore volume and shape effects were investigated by comparison between experimental and FEM results. Many different cases of pore closure behavior were observed and the FEM results were qualitatively well matched with experiments. Bonding strength of pore measured by tensile tests shows that there were disparity within several fully closed pores. Fracture surfaces show welded regions could be divided into Not, Partially and Perfectly welded regions. The pressure-time curves obtained from FEM results indicate that pore surface contact time and deformed surface length are also important parameters in pore welding. Finally, reduction ratio, pore shape, pore angle and slab thickness were considered as process parameters to make pore closure maps.