Influence of Hot Ni Shot Peening on Surface Hot Shortness

Steel scraps are used as a resource of electric steel making. However, reuse of the scrap leads to increase the amount of tramp elements such as Cu and Sn. In hot rolling process, Cu segregates at the scale/steel interface. Furthermore, this Cu segregation layer causes surface cracking. This brittleness is called surface hot shortness. Previous studies have shown that surface hot shortness is suppressed by addition of Ni. However, the addition of Ni increases in the cost of steel making.