PENGARUH JENIS ELEKTRODA DAN VARIASI ARUS PADA PENGELASAN PIPA BAJA ASTM A53 TERHADAP NILAI KEKERASAN DAN STRUKTUR MIKRO

Abstract

Welding is a technique of joining a metal using heat energy until it becomes liquid or melts. Pipeline is a means of transportation to move liquids or gases such as crude oil, water, and natural gas. This study aims to determine the effect of electrode type and welding current on the hardness value and microstructure of ASTM A53 steel pipes, by varying the electrodes, namely RB-26 E6013 and LB-52 E7016, also varying the current 90A, 100A, and 110A. This research uses ASTM A53 steel pipe material with a thickness of 3.91 mm. The type of connection used is double weld butt joint V-Groove angle 60^o. The tests carried out were Vickers hardness test and metallographic test. The results of the study obtained the highest hardness results occurred in the welding process using RB-26 E6013 and LB-52 E7016 electrodes at a current of 110A with a result of 152.3 HV, while the lowest hardness value occurred in LB-52 E7016 and LB-52 E7016 electrodes at a current of 90A with a result of 108.3 HV. The results of microstructure testing on electrodes RB-26 E6013 and LB-52 E7016 martensite grains are most abundant at a current of 110A in the weld metal and HAZ, while on electrodes LB-52 E7016 and LB-52 E7016 martensite grains in the weld metal are most visible at a current of 110 and in the HAZ at a current of 100A, and on electrodes RB-26 E6013 and RB-26 E6013 martensite grains are most abundant at a current of 90A in the weld metal and HAZ areas.

Keywords: SMAW Welding, Welding Current, Electrode, Hardness and Microstructure, ASTM A53 Steel Pipe.