Research and Development > JFE TECHNICAL REPORT >JFE TECHNICAL REPORT No.20 March 2015 - Special Issue on “Steel Plates” and “Welding and Joining” > Method of Improving Fatigue Strength by Peening on Base Metal and Development of Mechanized System

No.20 March 2015 - Special Issue on “Steel Plates” and “Welding and Joining”

Method of Improving Fatigue Strength by Peening on Base Metal and Development of Mechanized System

NAKANO Takashi      NAKANISHI Katsuyoshi      MORIKAGE Yasushi

Abstract

Hammer peening is used for improving fatigue strength of welded joint. In general peening method impacts are introduced on the weld toe, however, in this new method impacts are introduced on the base material near the weld toe. Since impacts are introduced on the flat base metal, this method does not affect the quality of the weld and stable fatigue strength can be achieved. Through finite element (FE)-analysis, the correlation between the area of depression and the fatigue strength was confirmed, and the threshold level required for improving fatigue strength was defined. Also in order to expand applicability, faster treatment method by using mechanized system was developed.

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