Effect of shot peening on fatigue strength of friction welded joint with flash under the condition of the various carbon steel for machine construction

Abstract

Effects of base metal hardness on improvement of fatigue strength by shot peening treatment are investigated using various carbon steels for machine construction. Furthermore, an effect of shot peening treatment on improvement of fatigue strength of friction welding is investigated.
The results are summarized as follows.
1) The improvement of fatigue strength by shot peening treatment is effective in the case of harder material on using the high carbon steel.
2) Fatigue strength of a friction welded joint becomes higher than the base metal although the flash does not be removed if shot peening treatment is applied.
3) The fatigue strength increases in proportion to the raise in hardness near the surface in the both cases of base material and the one with shot peening treatment.