Hardness analysis on carburized steel weld joint by SMAW using different welding current

Abstract

Low-cost weld joint on wear-resist gear train component was introduced for replacing conventional bolted connection to avoid its additional material and holes requirement. This study was concerned on the hardness analysis of carburized steel weld joint generated from SMAW with different welding currents, namely 80, 100, and 120 A. The results indicated that the hardness is decreased at HAZ and subsequently increased at weld metal for all samples. On the other hand, the highest welding current applied during welding shows the highest hardness curve among the other currents up to 226.5±2 HV at weld metal. By micro-and macrostructural analyses, phases evolution during thermal cycle on welding process played the crucial role to determine the hardness of HAZ, while the weld metal hardness was dominantly driven by the carbon-rich element distribution.