Preheating Temperature Effect on Flux-Cored Arc Welding (Fcaw) in 3g Position on Steel Plate Towards Tensile Strength and Hardness

Every process, whether planning, testing, or production, must meet established standards and be conducted professionally. Professionalism means that processes are carried out correctly, from procedures and implementation to analysis and decision-making or conclusions. This prevents undesirable outcomes and ultimately ensures the sustainability of the company or its operations. This research was conducted to fulfill the professionalism standards in studying the effect of preheating temperature on welding results, especially on the mechanical properties of the weld, in this case, the tensile strength and hardness of LR Grade (AH36) steel plate welds. This research used the Flux-Cored Arc Welding (FCAW) process with variations in preheating temperature: without preheating, 100°C, and 200°C. The tensile test results showed that the specimen without preheating had the highest tensile strength of 530.28 MPa. Among the preheated specimens, the specimen with preheating at 200°C had the highest average tensile strength of 518.79 MPa. Therefore, it can be concluded that increasing the preheating temperature of the material decreases its tensile strength. Hardness observations showed that higher preheating temperatures caused a decrease in the hardness of the base metal and the Heat-Affected Zone (HAZ), while the hardness of the weld metal increased. Based on these two parameters, it can be concluded that preheating is not optimal for flux-cored arc welding (FCAW) with LR Grade (AH36) material.