PENGARUH PROSES POST WELD HEAT TREATMENT (PWHT) PADA PENGELASAN SMAW TERHADAP KEKUATAN TARIK BAJA ST 60

Abstract

Effect of Post Weld Heat Treatment (PWHT) Process on SMAW Welding on Tensile Strength of ST 60 Steel. This study aims to determine the effect of variations in holding time 30 minutes, 45 minutes, and 60 minutes after undergoing the welding process using the SMAW welding method. The electrode used is RD-260 with a diameter of 2.6 mm. The type of seam
used is V seam with an angle of 60o. The current used is 100 Ampere, the tests carried out are tensile strength, hardness (vikers), and microstructure. This research was conducted at the Materials Testing Laboratory of the Department of Mechanical Engineering, Faculty of
Engineering, Tadulako University. The results of the tensile test showed that the tensile stress strength at a holding time of 60 minutes had the highest value of 704.61 MPa and the lowest value of holding time of 30 minutes was 683.77 MPa. For tensile strain, the highest value is at a holding time of 60 minutes, which is 33.86% and the lowest is at a holding time of 30 minutes, which is 31.58%. For the modulus of elasticity, the highest value is at a holding time of 60 minutes, namely 5383.16 MPa and the lowest is at a holding time of 30 minutes, which is 5111.77 MPa. The highest average hardness value is found at a holding time of 30 minutes, which is 195.059 Kg/mm2 which is located in the
welding area and the lowest at a holding time of 60 minutes, which is 160.938 Kg/mm2, which is located in the base metal area. The results of the microstructure in the weld area and HAZ show that the structure of ferrite and pearlite grains is more dominant.

Keywords: Holding time, SMAW, ST 60 Steel, Tensile Strength, Hardness, and Microstructure