|
Vol.36, No.2, 207 ~ 217, 1998
|
| Title |
| Cracking Phenomenon during Hot Rolling of Non-oriented Electrical Steel Sheets |
| 한명환 , 이성학 , 김낙준 , 변귀환 Myung Hwan Han , Sung Hak Lee , Nack J . Kim , Gwi Wan Byun |
|
|
|
| Abstract |
| An investigation was conducted into the effects of microstructural parameters on the cracking which often occurred in the edge parts of hot rolled non-oriented electrical steel sheets. Particular emphasis was placed on the role of iron oxide particles and ferrite grain shape in the cracking phenomenon. Detailed microstructural analyses of the sheets showed that highly elongated, fine grains were predominantly found in the edge region because of the less dynamic recrystallization, whose hardness was higher than that of the center region. A number of oxides were also observed in this edge region, and initiated intergranular or cleavage cracks when the edge part was impacted by side guide rolls during rolling. These oxides were identified to be Si- and Mn-containing iron oxides which might be formed during continuous casting process. In addition to edge cracks, line scabs were found in a linear mode parallel to the rolling direction on the surface of the edge region, probably due to severe oxidation during hot rolling. Thus, the minimization of oxides and highly elongated grains in the edge region and the careful control of the gap between sheets and side guide rolls were suggested to prevent the edge cracking. |
|
|
| Key Words |
|
|
 |
|
