Mechanical and physical properties improvement of S275J2 welded carbon steel

In the present research, the effects of post weld heat treatment on the mechanical and physical properties of S275J2 welded Carbon steel by Shielded Metal Arc Welding are analyzed. The material is commonly used in metal construction, base plate of wellhead, metal composite and concrete. The micro structure testing, Charpy-V-Notch Impact testing, and hardness testing were done focusing on specific regions, namely base metal, heat affected zone, and weld metal. The result of hardness test showed that there is a decrease of hardness value after post weld heat treatment. Meanwhile, the result of impact test showed that impact energy for metal base, heat affected zone and weld metal of welded material without any post weld heat treatment are lower than those with post weld heat treatment. Moreover, the results of microstructure test showed that the grain size of welded material without post weld heat treatment is finer than welded material with post weld heat treatment. Meanwhile, welded material with and without post weld heat treatment has the same microstructure but the grain pattern of the structure on welded material with post weld heat treatment process is more uniform and evenly distributed in compared to those of welded material without post weld heat treatment.