高碳钢盘条电阻对焊失效分析

高碳钢盘条焊接区质量是影响高应力钢绞线生产效尺寸较大及材料成分不一致等,常在焊接区发生断丝现象.通过对大量的拉丝及绞线时的断裂试样进行分类、统计,并结合实际工况条件,对试样的断口形貌、微观组织进行了分析.结果表明:焊接区在拉丝工序中引起的断裂占64.1%,在绞线工序中引起的断裂占35.9%.引起焊接断裂的主要原因是焊缝处的夹杂及氧化物、焊接热影响区的过热组织及网状渗碳体、及拉丝过程中的表面形变硬化.阐明了焊接质量主要受焊接工艺、焊后热处理、去疤后的表面润滑影响.

Failure analysis of upset butt welding for high carbon steel

The weld quality of upset butt welding of high carbon steel bull rod is the key to ensure the uninterrupted and highly efficient pro- duction.But the fracture is often found within the welding area due to its poor weldability,large size and disagreement of chemical composi- tion.The fracture microphotograph and microstructure were analyzed through the classification of fractured samples and statistic of actual work- ing condition for drawing and roping.The results show that the proportion of welded joint which broken in the drawing process was about 64. 1%,and about 35.9% in the roping process.The failure reason of welded joint was due to the impurity and oxide in weld,the overheated mi- crostructure and network cementite in HAZ and surface hardening resulting from the process of drawing,so that the quality of welded joint will be mainly affected by welding technology,postweld heat treatment and the surface lubrication after removing welding scar.