Abstract
The basic fatigue strength with correspond the fatigue strength of welded structures containing high tensile residual stresses of yield strength magnitude was obtained by the σmax=σy test. This test method was confirmed to be useful even for specimens containing high tensile residual stresses of yield strength magnitude. The basic yield strength was decreased with the increase of the yield strength of material. Based on this result, following proposals are given in order to increase the fatigue strength of welded structures by reducing the tensile residual stresses.
(1) Use of low yield ratio materials.
(2) Use of low transformation temperature materials.
(3) Use of low yield strength weld metals for the passes which form the part of fatigue crack initiation.
(4) Use of welding methods which bring the early cooling of surface area of plate.
