Numerical and experimental investigations on the modification of as-welded residual stress after local material removal

Abstract

The detailed procedures of experiments and numerical simulations to investigate the modification of as-welded stress after milling a local region from the welded plate are presented. A three-dimensional (3D) finite element model was employed to simulate the residual stress induced by multi-pass welding. Taking the as-welded residual stress as the initial stress state, the stress modification of as-welded stress by local material removal with a mill process was also numerically investigated. A welding experiment, milling process, and stress measurements were carried out to validate the numerical analysis. The local material removal with a milling process was considered as a simple stress relief process during the finite element simulation, which was validated by the experimental results. With the proposed numerical model, the modification of as-welded through-thickness stress owing to local material removal was discussed. Investigated results showed that less local material removal does not seem significantly to influence the stress distribution and magnitude at the weld centreline; by increasing the thickness of the material removal, the through-thickness transverse stress within the weld zone changed more noticeably than the through-thickness longitudinal stress, while within the region far from the weld seam, the through-thickness longitudinal stress largely increased, as opposed to the through-thickness transverse stress, which changed little.

Experimental study on the whole‐life heterogeneous ratchetting and ratchetting‐fatigue interaction of SUS301L stainless steel butt‐welded joint

“…In the preparation of the present specimens, the residual stress was released significantly by the cutting process . Therefore, the impact of residual stress on the experimental result is ignored in this work.…”

“…In the preparation of the present specimens, the residual stress was released significantly by the cutting process. 10,[48][49][50] Therefore, the impact of residual stress on the experimental result is ignored in this work. Simultaneously, referring to the experimental results in Luo et al, 10 it was seen that the hardness in FZs was the lowest one in the whole welded joint (ie, 285 HV for BM, 196 HV for FZs, and the hardness in HAZ varied gradually from that of BM to HAZ 10 ) and the strain concentrated in FZs, which could make sure that the fatigue failure occurred in such subzones.…”

Effect of pass increasing on interpass stress evolution in nuclear rotor pipes

“…2 Experimental measurement of residual stress during welding has some practical limitations, and the experimental measurement can be conducted commonly after the whole welding process has been complete or after post-weld heat treatment (PWHT). 3,4 Owing to the relatively large wall thickness in nuclear rotor piping systems, the welded joints are often constructed of a large number of weld passes. At this time, it is difficult to determine the distribution and evolution of residual stress states during welding by experiment.…”