基于690镍基合金多层多道焊脆性温区模拟数据的裂纹判据研究OA

During the multi-layer multi-pass welding process of high-temperature nickel-based alloys,the action of multiple thermal cycles readily induces ductility-dip cracking(DDC)within the weld metal.This poses potential safety hazards dur-ing service,and is of particular importance in applications for nuclear power structures.To address this issue,this study,fo-cusing on the temperature factor within these multiple thermal cycles,conducted experimental and numerical simulation re-search on multi-layer multi-pass welding of high-temperature nickel-based alloys.Based on simulated thermal cycle tem-perature data for the cracking region,the relationship between the dwell time within the brittle temperature range(BTR)of the alloy and crack initiation in the multi-layer multi-pass weld cracking zone was investigated,thereby establishing a crack-ing criterion derived from the simulated thermal cycle data.Firstly,single-pass welding experiments and numerical simula-tions were performed to validate the simulation model.Secondly,multi-layer multi-pass welding experiments and simula-tions were conducted;simulation data extraction points were determined based on experimentally identified crack locations,enabling the acquisition of temperature characteristics associated with cracking.Based on this research,it was ultimately de-termined that a dwell time between 71.7 s and 88.1 s within the brittle temperature range,occurring near the edge region of the test component,constitutes a susceptibility zone for cracking in high-temperature nickel-based alloys.This study pro-vides a technique for crack susceptibility assessment in high-temperature nickel-based alloys based on simulated tempera-ture data.