| Residual stress and fatigue of welded 0.22%C carbon steel were studied by X-ray diffraction method. The macroscopic and the microscopic rediual stresses were measured by shift of diffraction peak, and broadening of integral breadth, respectively. The distribution of residual stresses, tensile on welding zone and compressive near the side end of welding zone, were found. The effect of residual stresses on fatigue were not so significant. These residual stresses and integral breadth during the fatigue process were changed in three stages by cyclic stressing as follows. On the first stage compressive residual stress and rapid increase in integral breadth were found, on the second stage the compressive stress which found in the first stage was decreased rapidly and the integral breadth was increased slightly, on the third stage the gradual increase in compressive residual stress and the rapid increase in integral breadth were noticed. |
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