Papers by Keyword: Fine Grain Steel

Abstract: This study investigates mechanical and microstructural properties of P460N steel after Shielded Metal Arc Welding (SMAW). Three specimens with groove angles of 45 °, 60 ° and 75° were prepared and welded for this purpose. Tensile strength test, impact test, grain size test, macro and micro hardness test and metallographic test were performed on weld metal (WM), Heat Affected Zone (HAZ) and Base Metal (BM) and the results were compared. In the specimen with groove angle of 60°, yield strength was more than the base metal. Impact energy results in HAZ were different, so that HAZ areas in the specimens with 45° and 60° groove angles have less impact energy compared to the base metal but in the specimen with 75° groove angle, impact energy was more than the base metal. This increase can be due to formation of intermetallic compounds. After checking mechanical and microstructural properties of all the specimens, the groove angle of 60° was confirmed to be used at designing and construction of a reservoir with thickness of 14mm and working pressure of 40 bars.

Abstract: Recently, the study of fine grain steels aimed at achieving into high strength has become active. Welding is one of the most effective methods for connecting the structural components. For those cases, the negative influence of any residual tensile stress induced during the welding process must be considered. It has been proved that shot-peening can effectively solve this problem. However, the influence of the Shot-Peening process on fine grain steels after welding has only been briefly reported up to now. In this study, fine grain steels were used, and specimens were obtained after heat treatment. Residual stress distributions near the surface of the fine grain steel after shot-peening were measured by X-ray diffraction technology. Moreover, the effect of hardness on distributions near the shot-peened surface was also estimated.