SEDL / STP / STP993-EB / STP26362S

Vibratory Stress Relief of Welded Parts

Bouhelier, C


Barbarin, P


Deville, JP


Miege, B
Engineers, Centre Technique des Industries Mécaniques (CETIM), Senlis,

Pages: 14    Published: Jan 1988

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Abstract

What is the efficiency of residual stress relieving by mechanical vibration? In this paper, studies were carried out on two primary welded reducer gear boxes weighing 1200 kg each, which were thermally (A box) and mechanically (B box) stress relieved. X-ray stress measurements were made in both cases before and after relieving. Dimensional measurements were made on the B box. During the mechanical treatment the dynamic behavior of the box was followed by acceleration measurements and extensometric testings, in order to estimate the magnitude of the vibration-induced stresses and to detect the eventual presence of a new permanent strain. In the case of thermal relieving, the reduction of residual stresses is about 70 to 100 %. In the case of mechanical relieving, the reduction is between 45 to 100 % for tensile stresses, whereas it is only 0 to 45 % for compressive stresses. Some tests were performed on welded parts of a pump unit component, and the results are similar to the preceding.