PENGARUH KEKERASAN TERHADAP VARIASI HEAT INPUT SAMBUNGAN LAS TAK SEJENIS PADA BAJA KARBON A36 DAN BAJA TAHAN KARAT (AISI 304)

Welding is one of the combining methods used to connect metal or metal parts, where this connection utilizesheat energy from the welding machine used in welding. In the welding process melting occurs between the filler metaland the welded metal. Welding strength is influenced by many factors including heat input, current strength, filler andflux, weld speed and cooling rate. This study aims to determine the effect of heat input on the value of hardness indifferent materials. In this study, the A36 Low Carbon Steel Plate was connected with 304 Stainless Steel plates usingAWS A5.4: E-309L-16 stainless steel electrodes with SMAW welding system. The test results show that the greater thewelding heat input, the lower the value of hardness. At low heat inputs, the rate of cooling will be faster, so that thecrystal will form martensite on a surface that has hard properties. Whereas in high heat input the cooling rate will beslower, at room temperature the crystal will form a softer and more ductile perlite