Analysis of bending deformation behaviour during circumferential welding of cylindrical parts: study of deformation behaviour at micron to sub-micron level of laser-welded automotive parts

摘要

This study describes experimental and theoretical analyses to interpret the bending deformation generated during circumferential welding of cylindrical parts by laser. The deformation behaviour (magnitude, direction) is examined in detail with consideration of the deformation mechanism concerned. The analytical results are used to propose a method of welding distortion control for use on actual production lines and to investigate method application. The results obtained may be summarised as follows. 1 The temperature history during laser welding is measured and compared with theoretical analysis results. The temperature history as welding progresses shows good conformity with the observed surface temperature distribution data. The deformation behaviour also shows a complex pattern of increase - > decrease - > increase - > decrease as the welding heat source progresses. 2 The deformation generated during circumferential welding of cylindrical parts by laser can be interpreted as depending on the processes of expansion and contraction in the welding range as welding progresses 3 Based on the deformation mechanism, deformation control can be performed through appropriate control of the welding starting position and amount of overlap. In future, to ensure further development of welding technology for deformation control, it is planned to undertake further deformation behaviour analyses and to establish a stable and generally applicable technology. To enhance the accuracy of deformation simulations, it is intended to establish an analytical technique able to predict the welding process on the basis of deformation predictions.