Premium
A study on weldability of zinc‐coated steel sheets in lap joint configuration
Author(s) -
ElBatahgy AbdelMonem
Publication year - 1997
Publication title -
steel research
Language(s) - English
Resource type - Journals
eISSN - 1869-344X
pISSN - 0177-4832
DOI - 10.1002/srin.199701714
Subject(s) - welding , materials science , metallurgy , electric resistance welding , weldability , flash welding , laser beam welding , heat affected zone , spot welding , ultimate tensile strength , arc welding , porosity , composite material , filler metal
The weldability of Zn‐coated steel sheets 0.7 mm thick was investigated using resistance spot welding process. The effect of welding current, welding time and holding time on weld nugget characteristics, microstructure, and mechanical properties was discussed. Then, the possibility of replacing this welding process with laser beam welding was outlined. In this respect, quality of weld joints as a function of zinc removal by grinding prior to welding was evaluated. It is found that resistance spot welding current and time are the most significant parameters in affecting both expulsion and Zn‐induced porosity. Expulsion was avoided and Zn‐induced porosity was reduced with the decrease in welding current and/or welding time. Zn‐induced porosity was completely eliminated by zinc‐removal by grinding prior to welding. The best weld joint concerning nugget characteristics, soundness and tensile shear strength was obtained using welding current of 10 kA, weld cycle of 20, holding cycle of 18. Unlike resistance spot welds, high quality of CO 2 laser welds free from Zn‐induced porosity could be made without zinc removal by grinding before welding.