STRUKTUR MIKRO DAN KEKERASAN BAJA S45C PADA PENGELASAN SMAW DENGAN VARIASI MEDIA QUENCH
<p>The purpose of this research is to find out the effect of current on microstructure and hardness value in S45C steel before (raw material) and after welding using Shielded Metal Arc Welding (SMAW). This research using experiment method. The Technique of data analysis using descriptive comparative research. The instruments that used for testing microstructure and hardness is Olympus Metallurgical Microscope and Vickers Hardness Tester. Based on the results of the research conclude that (1) the results of the microstructure testing showed the improved martensite structure after welding. In the raw material, martensite structure didn’t exist but the result of SMAW welding methods using quenching media of water, oil, and air that showed martensite structure was exist. (2) The hardness value of raw material is 232 VHN. The specimen with water media had highest average hardness value that is 411 VHN, oil media had average hardness value that is 308 VHN, air media had lowest average hardness value that is 263 VHN. This research showed that the result of SMAW welding using varying quenching media can changed the microstructure and hardness of S45C steel.</p>