Uji Kekuatan Tarik Sambungan Las Smaw Pada Baja Astm A36 Dengan Variasi Media Pendingin Air, Oli Sae 10w-40 Dan Udara

Welding is one of the essential processes in the manufacturing industry. One of the factors that affects the quality of welding results is the cooling medium used after the welding process. This study aims to determine the effect of different cooling media on the tensile strength of SMAW (Shielded Metal Arc Welding) welded joints on ASTM A36 steel. Three types of cooling media were used air, water with a pH of 6.5–8.5, and SAE 10W-40 oil. The welding process was carried out using an I-groove with a butt joint in the 1G position, using an E7018 electrode with a diameter of 3.2 mm and a current of 100 A. The tensile tests were conducted according to the ASTME8 standard.The results showed that the specimens cooled with SAE 10W-40 oil produced the highest average tensile strength of 574.9974 megapascal and the highest average elongation of 38.73%. Cooling with water resulted in an average tensile strength of 566.5932 megapascal and a maximum elongation of 28.27%. Meanwhile, cooling with air resulted in the lowest average tensile strength of 545.5592 megapascal and an elongation of 30%. The highest modulus of elasticity was obtained from water cooling at 2051.55 megapascal, followed by air at 2048.60 megapascal, and the lowest was from oil at 1493.83 megapascal.Based on these results, it can be concluded that the variation of cooling media affects the tensile strength of welded joints. Cooling with SAE 10W-40 oil provided the most optimal results, producing the highest tensile strength and good ductility. Therefore, SAE
10W-40 oil is recommended as the best cooling medium for the SMAW welding process on ASTM A36 steel, especially in ship hull applications.

Keywords: SMAW, ASTM A36 Steel, cooling media, tensile strength, I-groove, butt joint, ship hull.