| Title |
The Effects of In-cast Strand Deformation on Slab Qualities |
| Authors |
이주동(Joo Dong Lee); 임창희(Chang Hee Yim) |
| Keywords |
Slab bulging; Strand deformation; Roll misalignment; Roll gap profile during casting; Measurement of bulging; Band shape center-segregation; Transversal corner crack; High temperature creep; Roll displacement |
| Abstract |
Strand deformation is induced by bulging, roll misalignment and strand passline condition(roll gap profile during casting) and has a major role in formation of various defects such as crack and segregation. In order to prevent excessive slab deformation during casting, it is essential to predict how strand is deformed through on-line measuring of displacement. In the present paper, bulging measuring system has been developed to diagnose strand deformation during casting and its effects on slab qualities has been discussed, Excessive pressing by pinch roll, which was concluded to be a main reason of band shape centerline-segregation, was successfully predicted by on-line displacement measuring. And band segregation could be removed by reducing pinch roll pressure. Diagnosing of strand stoppage reveals that large bulging is induced with time by high temperature creep and causes large fluctuation of displacement after casting restart. In-cast roll gap profile in the casting direction can also be predicted by measuring roll displacement in the straightener and horizontal zones. In addition, the frequency of transversal corner crack has been reduced by improvement of in-cast roll gap profile. |