Investigation on microstructure and tensile shear properties of 9Cr oxide dispersion strengthened steel resistance spot welded joint

Resistance spot welding is employed to join the 9Cr oxide dispersion strengthened steel and the effects of different welding parameters are studied. Within the ranges of parameters used in this experiment, the failure load and energy increased from 4.3 kN, 1.0 J to 6.8 kN, 7.5 J as the welding current increased, while as the electrode force increased, the failure load and energy first decreased from 6.8 kN, 3.8 J to nearly 4 kN, 1.2 J, then remained stable. As the welding current exceeded 12.8 kA, the failure mode changed from pull out failure along the fusion line to the pull out failure along the fusion line partially and base metal partially. The welding current and electrode force strongly affect the mechanical properties and fracture mode of the joint.

Automated summary

Resistance spot welding is used to join 9Cr oxide dispersion strengthened steel, and the effects of different welding parameters are investigated. The failure load and energy increase with welding current, reaching 6.8 kN and 7.5 J respectively. However, the failure load and energy decrease initially and then stabilize with increasing electrode force. When the welding current exceeds 12.8 kA, the failure mode changes partially from pull out failure along the fusion line to pull out failure along both the fusion line and the base metal. The welding current and electrode force have a significant impact on the mechanical properties and fracture mode of the joint.