Mechanical Properties and Microstructure of the Repeated Weld-Repairs of Austenitic Stainless Steel Plates

Joining Most of the repair weld of parts and components cannot be avoided in any manufacturing industry. Weld procedure is commonly used to ensure the welded parts can be useful and safe. Weld repairs have to be carried out with suitable care and avoid premature failures of the weld components. The weld repairs often occur repeatedly on welded parts. Hence the investigation was done to evaluate the effects of repeated weld-repairs of austenitic stainless steels plates on both mechanical and microstructural properties. Weld samples were joined using gas tungsten arc welding (GTAW) with several numbers of weld repairs. The first weld was performed to join metal plates and assigned as 0R. The weld bead was then ground away and followed by the first weld repair using the same GTAW (designated as 1R). This repair process was continual until five times (identified as 5R). All specimen was characterized by the chemical composition test, the microstructure observation, and the mechanical tests. It was found that the HAZ hardness of repeated weld repair decreased when the number of repairs increased. The tensile test results of the repeated weld repair had a few effects on tensile strength. However, the result of the impact test on repeated weld repairs shows a substantial reduction in the toughness properties as the repeated number of weld repairs. The repeated weld repair influenced the mechanical properties of austenitic stainless steel plates and showed a tremendous decrease compared with the type of 304L stainless steel as the repeated numbers of weld repairs.