304 cold bending slingshot fracture

1, due to the poor thermal conductivity of steel, it did not burn through during rolling.

2. The steel has good plasticity at 900 ~ 1250℃, but it has great resistance to hot deformation. With the decrease of temperature during processing, the deformation resistance increases sharply, which is caused by controlling the finishing temperature too low. Usually, the final rolling temperature is not lower than 950℃.

3. When rolling stainless steel, the reduction rate and deformation degree of each pass are too large, so that the surface of the roll is not poured with cooling water. The maximum relative reduction should not be greater than 20%, and the maximum average elongation coefficient should not exceed 1. 18.

4. There is something wrong with the material, which may be caused by nonmetallic inclusions. In addition, I saw that only one corner of the billet was cracked, and the other three corners seemed to be fine. Is there a problem with the rolling process?