Investigation of the fatigue life of the fillet welded shafts

II SUMMARY MSc Thesis Investigation of The Fatigue Life of The Fillet - Welded Shafts Adnan ÇALIK Fırat University Graduate School of Natural and Applied Sciences Department of Metallurgy Education 1997 Page 57 The aim of the fillet welding is to repair the machine element or component worn or fatigued and thus reusing it. In this study, the welded-fatigue life of martensitic stainless steel used in producing of shafts was investigated. The aim of the study is to determine the fatigue life of the fillet welded martensitic-steel shafts. With this aim, the casted and forged specimens from AISI 422 martensitic stainless steel prepared according to DIN 32525-1 were applied fillet-welding with shielded stainless steel electrodes in 13 passes. The welds were applied with or without heat treatment. The heat treatments were tempering and pre-heating. The third specimen was welded without heat treatment. These specimens were then applied tensile and fatigue tests and the hardness of the welding region was measured by examining the microstructure. In the First chapter of the study the subject is introduced. In the second chapter, the mechanism of fatigue, the factors effecting fatigue and the methods of determining fatigue life are given. In the third chapter information about martensitic stainless steels and their welding are presented. In the forth and final chapter the experiments and their results are given. In this chapter there results are evaluated as well.