Verification of validity and generality of dominant factors in high accurate prediction of welding distortion

Abstract

When out-of-plane distortion was measured objecting to butt welding, if tack welding was easily performed, the position of a neutral axis was variously changed by the linear misalignment. Out-of-plane distortion was generated in the unexpected direction because the neutral axis changed. From such as bitter experience, a test specimen to measure out-of-plane distortion was proposed so as to solve this problem. Using the proposed specimen, out-of-plane distortion was measured for butt welding. In the high accurate prediction of welding distortion, the dominant factors, which were satisfying the yield condition (especially at high temperature above 700 degree Celsius) and regarding the weld metal as welds, had been specified in fillet welding previously. So as to verify the validity of the dominant factors, the experiment and thermal elastic plastic analysis by FEM were carried out using newly developed specimen for butt welding. The validity of the dominant factors in the high accurate prediction of welding distortion objecting to fillet welding was verified by the results of butt welding and its generality was confirmed. It was confirmed that residual stress was also highly predicted because welding distortion was highly predicted.