Pengaruh Kecepatan Putaran Spindel Dan Waktu Gesek Terhadap Kekuatan Sambungan Friction Welding Baja s45c Menggunakan Mesin Bubut

Abstract

This study aimed to investigate the effect of spindle rotational speed and friction time on the tensile strength and microstructure of S45C steel friction welded joints using a modified lathe machine equipped with a pneumatic pressing system. An experimental method was employed using spindle rotational speeds of 1170 rpm and 1800 rpm, with friction times of 70, 80, and 90 seconds. Tensile testing was conducted according to ASTM E8, while microstructural observations were performed on the base metal, Heat Affected Zone (HAZ), and weld interface using an optical microscope. The results showed that spindle rotational speed and friction time significantly affected the mechanical properties and microstructure of the welded joints. Increasing the spindle speed improved frictional heat generation and plastic deformation, resulting in stronger joints. The optimum friction time was 80 seconds, while a friction time of 90 seconds caused a slight reduction in strength due to excessive heat input. The optimum welding parameters were achieved at 1800 rpm and 80 seconds, producing the highest tensile strength of 881.84 MPa, an elongation of 11.33%, and a modulus of elasticity of 595.02 MPa. Microstructural observations revealed finer and more homogeneous grains due to dynamic recrystallization, resulting in stronger metallurgical bonding and improved joint performance.