冷镦钢线材表面微折叠缺陷原因分析及改进措施

冷锻钢最常见的质量问题为加工开裂，而导致加工开裂的常见原因为轧制折叠缺陷。对冷镦钢线材在轧制过程中出现的50 μm深微折叠缺陷的产生原因进行了分析，主要是轧制制度不合理、减定径孔型过充满、轧机孔型不对中、轧件存在轻微划伤缺陷而造成的。为此，对轧制压下量、孔型设计、轧制工艺备件进行了改进，杜绝了微裂纹缺陷的产生及冷镦开裂质量异议。

Cause analysis of micro-folding defects on the surface of cold heading steel wire and its countermeasures

The most common quality problem of cold heading steel was cracking,and a common cause of cracking was rolled folding defect.The causes of 50 μm deep micro-folding defects of the cold heading steel wire during rolling were analyzed.The main reasons were the unreasonable rolling scheme,overfilling of reducing and sizing pass, misalignment of rolling mill passes and slight scratches on rolled products.Therefore,rolling reduction,pass design and rolling process equipment had been improved.The micro-crack defects and cold heading cracking quality objections were eliminated.