Identification of Chemical Properties of ER307 Electrode in GMAW Welding for Physical and Mechanical Characteristics of Armor Steel

Gas Metal Arc Welding (GMAW) is a welding technique widely used in industry due to its efficiency and ability to produce high-quality weld joints. In this process, the selection of filler metal is an important factor that affects the mechanical properties and microstructure of the weld. One type of filler used is ER307, which is a high manganese stainless steel-based austenitic welding wire designed to join dissimilar metals or steels with high carbon content. The use of ER307 in the GMAW process provides advantages in increasing crack resistance and toughness of the weld, especially in joints that experience high stress or extreme environmental conditions. This study aims to identify the ER307 electrode in the Gas Metal Arc Welding (GMAW) process against the physical and mechanical properties of MIL-DTL-46100E armor steel. Characterization is carried out through EDS tests for microstructure observation, and Vickers hardness tests. The results show that the highest hardness value is in the HAZ zone (523 HV), while the weld metal reaches 324–328 HV, according to Defense Standard 03-34. The content of Mn and Ni in ER307 increases the combination of strength and ductility, while Zn plays a role in corrosion resistance. Thus, ER307 is proven to meet the requirements for welding armor steel for defense applications. The results show differences between the weld metal areas with higher hardness values. The influence of the welding process causes microstructural changes, especially in the HAZ area where the phase is dominated by the ferrite phase. Evidence of material strength in ER 307 electrodes has unique chemical properties by containing elements Manganese (Mn) and nickel which help improve the combination of strength and ductility of the material, and Zinc which has the property of protecting the material from corrosion to strengthen the properties of the joint material in accordance with the steel strength guidelines.