ESTIMATION OF CRACK GROWTH BEHAVIOUR IN HAZ OF SUBMERGED ARC WELDS OF STRUCTURAL STEEL

Abstract

The testing and analysis techniques such as FM studies and FEM analysis have been contributed for research and design in various areas of engineering and technology. The application of such technologies has resulted in more reliable welded structures. However, catastrophic failures are still common. Generally most of the weld related failures have been attributed from the heat affected zone (HAZ), which is believed to be the weakest link in the heterogeneous welded joint. Moreover, it is very difficult to estimate the properties of the HAZ due to microstructural gradient within a narrow zone. For this study work, experimental work was carried out on the HAZ obtained by Submerged Arc Welding process. The mechanical properties such as tensile strength, Charpy V — notch energy and hardness in weld metal and the base metal were compared. Fatigue crack growth rate test for the HAZ were carried out for different stress ratio of 0.1, 0.3, and 0.5 as per Paris law and Paris constants were determined for different stress ratio. The Paris constants were affected slightly at different values of stress ratios.