Engineering and Technology Journal

Abstract

The aim of this work is to study the effect of the time of shot peening with
steel balls of 1.25 mm in diameter on fatigue strength of butt joints for low carbon
steel (1020 AISI) welded by metal arc welding shielded with CO2 gas
(MIG/MAG). All fatigue tests were of the rotary bending type at mean stress of
zero for welded unpeened samples and shot peened samples at various times.
It was found that all the shot peen times of (10,20,30) minutes have improved
the fatigue strength and the best strength has been achieved at the time 20 minutes
because of the high compressive stresses induced by the shot peen process and in
addition to the denteritic microstructure in the weld zone for unpeened samples .