异种钢电阻塞焊工艺优化及接头性能分析

发布时间：2018-06-17 07:31

本文选题：高强钢 + 异种钢　；参考：《焊接学报》2017年07期

【摘要】：采用一种新型复合焊接工艺——电阻塞焊对1.5 mm等厚TRIP980高强钢/SPCC低碳钢板进行焊接,利用正交试验优化其焊接参数,随后增加焊前预热,分析对比无预热和焊前预热两种条件下较优焊接参数时接头的力学性能及组织、硬度特点.结果表明,各焊接参数对接头的拉剪载荷影响程度由大到小依次为焊接电流、填充物直径、焊接时间及电极力;在电极头端面直径为8 mm的条件下,填充物直径为5.5 mm时的接头力学性能优于其它直径;相同焊接参数时,焊前预热塞焊接头的拉剪载荷比无预热提高7%以上;两种条件下较优焊接参数时,焊前预热塞焊接头的熔核偏移量小于无预热,熔核和熔合区的硬度比无预热时有所下降,熔合区脆硬马氏体组织比无预热少;焊前预热塞焊接头断口为韧性断裂,无预热塞焊接头断口为脆性断裂;其主要机理是,预热减小了熔核区金属过热倾向,使熔核扩展均匀,熔合区脆硬组织减少,有利于接头强度的提高.
[Abstract]:A new type of composite welding process, electric blocking welding, was used to weld 1.5 mm high strength steel / SPCC low carbon steel sheet with equal thickness TRIP980. The welding parameters were optimized by orthogonal test, and then preheated before welding was added. The mechanical properties, microstructure and hardness of the joints under the optimum welding parameters were analyzed and compared with those without preheating and pre-welding. The results show that the influence of welding parameters on the tensile and shear load of the joint is in the order of welding current, filling diameter, welding time and electrode force, and when the end surface diameter of the electrode head is 8 mm, When the diameter of filler is 5.5 mm, the mechanical properties of joints are better than other diameters, and the tensile and shear loads of preheated plug welding joints before welding are more than 7% higher than those without preheating when the welding parameters are the same. The nugget deviation of preheating plug welding joint before welding is less than that without preheating, the hardness of fusion and fusion zone is lower than that without preheating, the brittle martensite structure in fusion zone is less than that without preheating, and the fracture surface of preheating plug welding joint is ductile fracture before welding. The fracture surface of welded joint without preheating plug is brittle fracture, and its main mechanism is that preheating reduces the tendency of metal overheating in the nugget zone, makes the nugget spread evenly, and reduces the brittle and hard microstructure in the fusion zone, which is beneficial to the improvement of the joint strength.
【作者单位】：内蒙古工业大学材料科学与工程学院;
【分类号】：TG453.9

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