82B盘条杯锥状断口断裂原因分析

Analysis on Fracture Cause of 82B Rod Cup Conical Fracture

某82B盘条为钢丝绳原料,进入拉丝模粗拉前两道工序时发生了杯锥状断裂。为此,通过金相显微镜和扫描电子显微镜分析了82B盘条杯锥状断口断裂机理。结果表明:盘条的的杯锥状断口形成机理主要是由于盘条芯部存在马氏体岛,导致沿芯部马氏体岛出现裂纹,随着进一步拉拔沿裂纹横向形成圆环状裂纹,纵向形成“V”型裂纹,最后断裂后形成“一尖一窝”的杯锥状断口。

A 82B wire rod,which was the raw material of steel wire rope,had a cup-cone fracture when it entered the first two processes of rough drawing of drawing die.Cup Conical Fracture of 82B wire rod was studied by OM and SEM.Results showed that the formation mechanism of cup-cone fracture was mainly due to the existence of martensite island in the core of the rod,leading to the cracks along the core martensite island.With further drawing,circular cracks were formed along the transverse direction of the crack,then,"V"cracks were formed longitudinally,and finally,cup-cone fracture was formed after fracture.