The relative effects of residual stresses and weld toe geometry on fatigue life of weldments

• Effects of residual stress and weld toe geometry on the fatigue life are studied.
• Residual stresses are varied by using two different welding filler materials.
• The use of Low Transformation Temperature consumables increase fatigue life.
• Residual stress has a larger effect than the weld toe radius on fatigue strength.

The weld toe is one of the most probable fatigue crack initiation sites in welded components. In this paper, the relative influences of residual stresses and weld toe geometry on the fatigue life of cruciform welds was studied. Fatigue strength of cruciform welds produced using Low Transformation Temperature (LTT) filler material has been compared to that of welds produced with a conventional filler material. LTT welds had higher fatigue strength than conventional welds. A moderate decrease in residual stress of about 15% at the 300 MPa stress level had the same effect on fatigue strength as increasing the weld toe radius by approximately 85% from 1.4 mm to 2.6 mm. It was concluded that residual stress had a relatively larger influence than the weld toe geometry on fatigue strength.