冷轧钢板HAZ组织性能对轮辋折纹缺陷的影响

EFFECTS OF HAZ MICROSTRUCTURE OF COLD ROLLED STEEL SHEETS ON LINE DEFECT

研究了二种不同成分 (钢 A和钢 B)的冷轧低碳钢板闪光焊焊接热影响区 ( HAZ) ,各区段的显微组织、性能及其对汽车轮辋焊后产生折纹缺陷的影响。结果表明 :碳当量较低的冷轧钢板 (钢 A)产生了折纹缺陷。钢 A顶锻时间较钢 B长 ,引起钢 A产生软化现象 ,发生软化的过热区宽度较宽 ,使焊接 HAZ的显微硬度与母材相比降低幅度较大。软化区宽度增大 ,软化区所受“约束强化”作用降低 ,当焊后进行机械冲孔时 ,引起HAZ软化区产生折纹缺陷。

Microstructure of weld heat affected zone(HAZ)of low carbon cold rolled sheets of two composition (steel A and steel B)and its effect on line defect has been investigated in this paper The experimental results show that the line defect is observed in cold rolled sheets of lower carbon equivalent It is because that compared with steel B,steel A have longer upsetting time with same welding procedure making HAZ softer and wider in contrast to base metal Therefore,effect of 'restrictive strengthening'is reduced HAZ soften region causes line defect when it is machined after welding