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Abstract: Studies
show that considering the mechanism of improving the fatigue
performance, ultrasonic peening and TIG dressing are complementary. A
new compound treating method of improving fatigue performance of
high-strength welded joint is that firstly treated the welded toe by TIG-dressing
and then performed ultrasonic peening. Test results indicated that: (1)
In the given range of stress level, contrasted with the specimens in as
welded condition the fatigue strength of the specimens treated by
ultrasonic peening is increased by about 95% and the fatigue life is
prolonged by 3.6～62 times. The fatigue strength of the specimens treated
by TIG-dressing is increased by about 34% and the fatigue life is
prolonged by 0.4～1.3 times. And while the fatigue strength of the
specimens treated by compound treating by TIG-dressing adding ultrasonic
peening is increased by about 120% and the fatigue life is prolonged by
28～125 times. (2) The fatigue strength can be even improved by compound
treating ultrasonic peening adding TIG dressing on the basis of
ultrasonic peening or TIG dressing. In the range of high stress,
contrasted with simple ultrasonic peening treating TIG dressing adding
ultrasonic peening compound treating has definitive predominance because
compound treating overcome the decreasing of fatigue performance
improvement of welded joint treated by simple ultrasonic peening.
Key words: Ultrasonic peening TIG dressing Compound treating by
ultrasonic peening adding TIG dressing Fatigue performance
CLC No: TP12
Received 20020422, received in revised form 20020906
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