Analysis of the Effect of Shielded Metal Arc Welding on the Blade of a Plastic Waste Shredding Machine to Determine Hardness Value

Abstract

This study aims to determine the hardness values of leaf spring steel material after undergoing a welding process using LB 52U electrodes. The specimens were tested using the Rockwell hardness method on the HRC scale in accordance with ASTM E18 standards. The hardness tests were conducted on three distinct areas: the weld metal zone, the heat-affected zone (HAZ), and the base metal (unwelded area), with five measurement points in each area. The results showed that the highest hardness was found in the base metal area, with an average of 81,78 HRC, while the weld metal area exhibited the lowest hardness, averaging 55,97 HRC. The HAZ displayed intermediate hardness values, averaging 72,82 HRC. The differences in hardness are attributed to microstructural changes caused by thermal effects during the welding process. These findings indicate that welding significantly affects the mechanical properties of the material, especially around the welded joint. This research can serve as a reference for selecting appropriate welding parameters to maintain optimal material performance.