82B盘条拉拔断裂原因分析

利用光学显微镜（OM）、显微硬度计（MS）、扫描电镜（SEM）等手段对82B拉拔断裂试样进行了分析。结果表明,82B盘条母材表面有擦伤现象,导致盘条在进入拉拔道次前即发生断裂,对此类断裂机理进行了探讨。拉拔断裂试样的表层出现马氏体（M）＋屈氏体（T）或表层硬化组织,进而在此类组织中出现V形裂纹或平行横裂纹,继续拉拔导致断裂。最后针对降低82B盘条拉拔断丝率提出了改进措施。

Drawing Fracture Cause Analysis of 82B Wire Rod

Drawing fracture samples of 82B wire rods were analyzed using optical microscope（OM）,micro-sclerometer （MS） and scanning electron microscope（SEM）.Results show that surface scratches are found on some wire rods which brought on fracture before drawn,and the breaking mechanism is discussed in the paper.V-type and parallel transverse cracking come into being in the martensite（M） and troostite（T） and hardening structure formed in the layer surface of samples,and continuous drawing resulted in breaking off.Finally,improving measures are put forward aiming at decreasing the drawing fracture rate of 82B wire rod.