| Title |
Side Cracking Phenomenon Occurring during Hot Rolling of Low-Carbon Steel Plates |
| Authors |
황병철(Byoung Chul Hwang); 이한상(Han Sang Lee); 김양곤(Yang Gon Kim); 이성학(Sung Hak Lee); 이대식(Dae Sik Lee) |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
Side cracking; Low-carbon steel plate; Hot rolling; Iron oxide layer; Pearlite band structure |
| Abstract |
In this study, a microstructural investigation was conducted on the side cracking phenomenon occurring in low-carbon steel plates during hot rolling. Particular emphasis was placed on the role of iron oxides and pearlite band structure in the side cracking. Detailed microstructural analyses of the hot-rolled plates showed that the pearlite band structure in the side region was considerably slanted to the surface, while that in the central region was parallel to the surface. Small cracks were often observed when the iron oxide layer formed by inhomogeneous oxidization along the slanted pearlite band structure in the side region was intruded into the plate interior during hot rolling. In addition to these small cracks, a few large cracks were also found when some protrusions formed on the plate surface were decarburized, folded, and then intruded into the plate interior. Thus, in order to prevent the side cracking, 1) the minimization of the segregation of C and Mn in slabs by the sufficient homogenization, 2) the parallel arrangement of the pearlite band structure in the side region by the appropriate control of the hot rolling process, 3) the minimization of the iron oxide formation by the shortest time exposed to high temperatures, and 4) the careful control of the spacing between steel plates and side guide rolls were suggested. (Received January 17, 2004) |