Initiation and development of 1.4539 austenitic steel welded joints made with TIG method and with laser beam

摘要

The paper presents the results of fatigue life tests of 1.4539 austenitic steel welded joints made with the TIG method and with laser beam taking into consideration the number of cycles to fracture initiation Ni and in their development conditions N_R. A significant influence of a shot peening process of the welded joints on fatigue life and contribution of numbers of cycles in the fracture course were shown. Analysis of fatigue fractures microfractography showed in the shot peened specimens a development of subsurface secondary fractures parallel to the outer surface of the tested welded joints. Tests on fatigue life and development of welded joints fractures were compared to analogical tests on the parent material.