Assembling of thick-section HSLA steel with one seam per layer multi-pass PC-GMA welding producing superior quality

Abstract

Assembling of 25-mm-thick HSLA steel plate with extra narrow gap between the plates is done with the help of multi-pass one seam per layer pulse current gas metal arc welding process maintaining vertical weld deposition. Assembling of thick plates is also made using conventional groove with commonly used procedure of multi-pass multi-seam per layer weld deposition. Distortion and shrinkage that developed in the weld joints have been suitably determined. The effects of welding parameters in reference to weld thermal behavior on shrinkage stress and bending stress have been studied. The observations show that the use of one seam per layer technique allowing extra narrow gap welding with properly selected parameters can improve quality of weld joint with respect to distortion and stresses. The effect of pulse parameters on weld quality is studied, correlated and discussed. Cost benefits of applying such a welding technique have been justified with respect to consumption of less filler material and time for preparation of weld joint.