Fracture toughness of type 316LN stainless steel welded joints

The fracture toughness of two types 316LN welded joints in different orientations at 300 K and 623 K in air was investigated. The tests were conducted using single specimen method, where J-R curves and fracture toughness values (J0.2) were obtained. Microstructure of the specimens were characterized before and after the test. Results show that 2GT welded joint exhibits higher toughness as compared to 5GT welded joint, and orientation has slight effect on the fracture toughness. Moreover, the fracture toughness drops remarkably with the increase of temperature.