Microstructure, Mechanical Properties and Failure Mechanisms of Resistance Spot Welding Joints between Ultra High Strength Steel 22MnB5 and Galvanized Steel HSLA350

作者：Liang, Xuebo; Yuan, Xinjian^*; Wang, Haodong; Li, Xiuyang; Li, Ci; Pan, Xueyu

来源：International Journal of Precision Engineering and Manufacturing, 2016, 17(12): 1659-1664.

DOI：10.1007/s12541-016-0192-8

• Ultra high strength steel
• Resistance spot welding
• Microstructure
• Mechanical property
• Fracture mechanism

Resistance spot welding of 22MnB5/HSLA350 and its weldability are investigated. From base material to the nugget, the microstructure of 22MnB5 side can be expressed as M/tempered M+ granular carbides/F+W/fine M/lath M, and on HSLA350 side, F+M/F+flocculent P+tempered M/F+flocculent P+M/F+M/lath M are observed. The heat-affected zone (HAZ) of 22MnB5 exhibits obvious softening region and strengthening region caused by the tempered M and quite fine M, respectively. The peak load of welded joints undergoes two stages of a dramatic increase and a subsequent decrease with increases in the welding current. The maximum value (13.82 kN) of peak load is achieved at a welding current of 8 kA. The failure modes involving interfacial failure (IF), pullout failure from the galvanized steel (PFG), pullout failure from boron steel and tearing of the galvanized steel (PFB-TG) and pullout failure from the boron steel (PFB) are discussed in detail.

• 出版日期2016-12
• 单位重庆大学