TWI Industrial Member Report Summary 8/1976
By J W Knight
Background
As an extension to earlier work, tests have been carried out on transverse nonload-carrying fillet welded specimens fabricated from both BS 4360 Grade 43A and high strength steel (685N/mm2 yield strength). Three grinding techniques have been studied and these are designated as follows:
i. Heavy disc grinding
ii. Toe burr grinding
iii. Full burr grinding
In addition, an investigation has been carried out into the effect of peening the weld toe region, with particular emphasis placed on the number of passes of the peening hammer along the weld.
All the techniques gave improved fatigue performance, with 4-pass hammer peening resulting in the greatest improvement as well as being the cheapest method of operation.
It should be noted, however, that the tests were carried out under constant amplitude loading and, since the benefits of peening result from the introduction of compressive residual stresses, the improvement might not be so great under variable amplitude service loading conditions.