Mohammad Honarpisheh - Assistant Professor, Faculty of Mechanical Engineering, University of Kashan, Kashan, Iran.
Hadi Mansouri - Phd student, Faculty of Mechanical Engineering, University of Kashan, Kashan, Iran.

Contour method is one of the methods used to measure residual stresses in a two-dimensional state. Residual stresses reduce the load tolerance, the life of the weld joints and deform the weld structures. The purpose of this study was to investigate the residual stresses on stress-relievedsamples in two methods on steel sheets of Ck45 and in the state of change in its metallographic structure before welding operations. In this study, using the Taguchi method of designing the experiments and the effect of input parameters on the residual stresses of Ck45 steel sheets wasinvestigated. In this regard, the results of experiments with changes in the type of aggregate by the method of normalizing the sheets and stress-relieving after the welding operation and its effect on the residual stresses due to welding by Co2 method was obtained. The results indicatedthat the optimal condition for reducing residual stresses after welding process obtained on normalized Ck45 sheet which was stress-relieved at the temperature of 650ºc and by 12 hours in the Stable state inside the furnace.

TIG Welding - Normalize- Stress relieving- Contour Method- Ck45 steel