冷轧辊坯中白点形成及预防的研究

Research on Flakes Formation in Roll Blanks of Cold Rolling Mill and Its Prevention

研究了冷轧辊坯中白点的形成原因及预防措施,结果表明,锻后经过扩散去氢,氢含量为0.6×10-6左右的MC5钢锻坯再次加热锻造后仍然会产生白点,这种白点是高温塑性变形中产生的内部裂纹。氢含量5×10-6左右的MC5电渣钢锭锻成530 mm的辊坯,采用适当的锻造工艺可以有效地防止白点产生,锻后缓冷48 h即可保证不产生白点。锻造中存在着裂纹产生与愈合的过程。

The formation and prevention of flakes in roll blank for cold rolling mill have been studied. The results indicate that the flake could still be formed during reforging process for the round bar which had already been subjected to forging and long time hydrogen diffusing, of which the hydrogen content is 0.6×10^-6, and these flakes are the internal cracks formed during high temperature plastic deformation. On contrary for MC5 steel ESR ingots with 5×10^-6 of hydrogen content forged into Ф530 mm roll blanks with suitable forging process and cooled down slowly for 48 hours after forging can affectively prevent the flakes formation. There are the cracks＇forming and recovering process during forging.