Mechanical Properties and Microstructure of Friction Mild Steel

Friction welding, one of solid-state welding methods, is very popular way to join cylindrical component since it offers many advantages over fusion welding problems in porosity and inside tightens of cooling leads to decreasing of joint strength. In order to produce sound welding by friction welding methods, a careful choice of welding parameter need to be carefully selected. The choice is in acordance with material of workpiece. Welding time is one of important process parameter since it governs the heat generated during weld and also affects coefficient of friction. Welding time variation of 30, 35, 40, 45, and 50 seconds was selected to investigate the influence of welding time to mechanical properties dan microstructure of friction welded S45C. Hardness test in Brinell and optical microscope was employed to present the hardness and microstructural changes in base metal, HAZ, and weld metal are. This research shown that in term of hardness, the weld metal has highest hardness followed by HAZ and base metal. The hardest area was produced by employing 35 and 45 seconds of welding time in weld metal area while the lowest was 50 seconds welding time in base metal area. For microstructure, weld metal area was superior than others area with HAZ strength decreases contained of pearlite of 69.17% and ferrite up to 30.83% while in the area of base metal, the strength decreased significantly with the contained percent of pearlite up to 68% and ferrite by up to 32%