DP780双相钢电阻缝焊接头组织及力学性能研究

Microstructure and Mechanical Properties of RSW Joint of DP780 Dual Phase Steel

  • 摘要: 采用窄搭接电阻缝焊方法焊接DP780双相高强钢板。利用扫描电镜(SEM)、显微硬度仪、电子万能试验机及杯突试验机对接头的显微组织、硬度、抗拉强度、塑性及断口形貌进行了研究。结果表明,熔核区主要由粗大的马氏体组织组成,焊接热影响主要是铁素体和马氏体组织,组织分布不均匀。DP780钢电阻缝焊接头具有较好的力学性能,由于粗大的马氏体组织,熔核区硬度最高。拉伸实验表明接头断裂在母材,接头强度高于母材;杯突实验表明,接头的塑性储备不足。

     

    Abstract: The resistance seam welding (RSW) test of DP780 Dual Phase Steel was carried out without preheating. The microstructure and mechanical properties of the welded joint were investigated by SEM, cupping tests and mechanical properties tests. The results show that the microstructure of the weld zone mainly consists of granular martensite. The microstructure of heat affected zone is mainly ferrite and martensite. DP780 Dual Phase Steel joint has good mechanical properties. The hardness of the weld zone is higher than that of base material and the heat affected zone of the joint. The tensile tests show the joint fractures at the base material, indicating that the joint strength exceeds that of the base material. However, the cupping test reveals an insufficient plastic reserve in the joint.

     

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