SAE6150盘条表面花斑缺陷原因分析及改进措施

针对客户反馈的SAE6150工具钢表面花斑形貌问题,对其宏观形貌和成分进行了检测分析,发现产生花斑形貌的直接原因是由于原料盘条表面存在不平整的微凹坑,平面和凹坑面在光的反射作用下呈现明暗不同的视觉色差,从而形成肉眼可见的花斑形貌。微凹坑产生的原因是盘条在轧制过程中表面残留氧化铁皮轧制压入而造成的;另外,盘条拉拔前的鳞皂化处理致使大量皂化液进入凹坑凝固后形成塞积物,盘条拉拔后凹坑难以去除而形成黑白相间的花斑形貌。为此,提出了相应改进措施,从根本上解决了热轧盘条表面缺陷问题。

Cause analysis and improvement measures for surface flecks defects of SAE6150 steel coil

In view of the surface flecks defects of SAE6150 tool steel by customer feedback,its macroscopic morphology and composition were tested and analyzed.It was found that the direct cause of the surface flecks defects was existing micro-pits on the surface of the raw material of wire rod.The plane and the pit surface show different visual chromatic aberrations of light and dark under the action of light reflection,thus forming a flecks appearance visible to the naked eye.However,the micro-pits were caused by the residual oxide scale pressed into the surface of the wire rod during the rolling process.In addition,the scale saponification treatment before drawing of the wire rod causes a large amount of saponification liquid to enter the pits and form pluggings after solidification.After the wire rod is drawn,the pits were difficult to remove and form a black-and-white flecks appearance.For this reason,corresponding improvement measures were proposed,and the problem of surface defects of hot rolled wire rod was resolved.