STUDY ON DISLOCATION STRUCTURES IN WELDED METALS UNDER FATIGUE LOAD

With TEM( Transmission ELectron Microscope),it hasbeen oberved and analyzed thatthe dislocationsarrangementsandthefatigue damageofeutectoid arein weled metals which were loaded at differentfatigueloads and load cycles.The resultsindicated thatthecharacter of fatigue damagein ferritesof welded metalsisthedislcationsarrangementchange and ieutec toidsof welded metalisthebroken cementites.This may be produced microcracks.