Significance analysis of weld and processing parameters on wall thinning and cross-sectional deformation of welded tube in nc bending process

The mechanical behaviors of different kinds of microstructure in weld joint reduce the ductility of the welded tube. In this study, the influences of these inhomogeneities and processing parameters on the deformation behaviors of welded tube are determined by the combination of orthogonal experimental design and finite element analysis. Five factors viz., weld position, push assistant level, mandrel shank diameter, number of balls and mandrel extension length are selected. The analysis of variance shows that push assistant level and mandrel shank diameter have significant influence on wall thinning △t, and number of balls has highly significant influence on cross-sectional deformation △D. The weld shows little effect on the deformation behaviors of the QSTE340 welded tube.