A study on resistance welding in steel sheets using a tailor-welded blank (1st report): Evaluation of upset weldability and formability

A press formability analysis of welded parts was studied in the current work, using a tailor-welded blank. For a body panel produced by the press forming of parts welded by the tailor-welded blank method, the following conditions are demanded: (1) The strength of the welded parts must be higher than those of the base metals. (2) After the welding, severe welding deformation must be avoided. (3) The press formability of the welded parts is similar to that of the base metals. (4) The reproductibility of the welding must be high. There are numerous welding methods satisfying these conditions, but the purpose of this study is to investigate the upset weldability and formability of a particular kind of material (SPCC). SPCC steel sheet shows good weldability and formability under some welding conditions. The experimental results are discussed by the evaluation of the results obtained from the tensile test, the hardness test, the microstructure and the Erichsen cup test. The formability of upset welded SPCC steel sheet as evaluated by the Erichsen cup test was little lower than that of the parent material.