Cause analysis of crack formation in root part of fillet weld of thick-walled joints based on computer simulation of strain-stress state during welding

Abstract

Computer simulation of thermal deformation processes occurring during welding of circular fillet weld of pipe T-joint made of S355 steel (in accordance with GOST 27772) is performed. Possible reason for the formation of unacceptable sizes discontinuities in the root part of multilayer weld — the growth of discontinuities from small to critical sizes in limited time interval as result of volumetric all-sided stretched stress state during the cooling period of the next root roller is determined based on the kinetics analysis of changes in the strain-stress state during welding.