An Experimental Study to Investigate the Effect of Repair Welding Repetition at the Joint on the Tensile Strength of Welded Segment

Steel is extensively used in the construction industry and, welded joint is a conventional type of steel joints. It is important that the welding quality should comply with standard terms and consistent with the contract. If the terms are not met and the quality of weld is poor, corrective actions (repairs) should be taken in accordance with the standard. Once the corrective actions (repairs) have been completed, the piece (the weldments) must be re-inspected, tested and checked in accordance with the requirements, and the conditions and causes of defect should be carefully reviewed and resolved. Fixing unacceptable welding defects is simply called "welding repair". This study, investigates the effect of repeated welding repairs on tensile properties of the component in the welding area. To this end, four samples (samples without repair, one repair, two repairs and three repairs) with thicknesses of 10 mm and 20 mm, were welded unilaterally (v shape), and an evaluation of tensile strength was implemented. The results show that for samples with the thickness of 10 and 20 mm, the mean yield stresses and the ultimate stresses of three repair welds increase compared to original welds. Furthermore, the failure in tensile often occurs out of the heat-affected zone and the tensile strength of mild steel (st37) subjected to three repairs is acceptable in the welding area.