Analysis of residual stress in 1.4539 austenitic steel joints welded with TIG method

The article compares the results of tests of residual stress determined based on Knoop microhardness measurements and obtained experimentally with the use of an x-ray diffractometer. Distribution of residual stress in the weld after strengthening of the surface layer, resulting from shot peening, was specified. A method of residual stress determination proposed by Oppel, based on Knoop microhardness distribution, was applied. An analysis of residual stress of 1.4539 austenitic steel welded joints, made with the use of TIG method and additionally strengthened with shot peening of the surface, showed good agreement of the results obtained both with the sin2y method and based on the microhardness measurement. The highest compression stress has occurred in a so-called Belayev point, approximately of 35 ÷ 40 μm from the surface. Keywords: residual stress, welded joints, TIG, Knoop microhardness, shot peening.