Delayed Cracking in High-Strength Steel Weld with Angular Distortion

概要

論文の詳細を見る
Delayed toe cracking in a low alloy high-strength steel weld with angular distortion was studied with the NRIM TRC (Tensile Restraint Cracking) test. A delayed toe crack initially occurred at a few millimeters below the concaved surface where the restraining stress was maximum by bending, propagated along the bond of a weld, and fractured the joint when the restraining stress was high. Possibility of delayed cracking in fabrication and during hydraulic test of a pressure vessel was discussed from results of TRC test, and all welds in this study were considered safe from the cracking in fabrication. As the results of TRC test in the corrosive environment, being limited to a newly developed steel of Mo-Nb-B type, this steel was considered particularly safe from the cracking in a welded joint during hydraulic test. Delayed cracking of the joint was not promoted in water environment. The submerged arc weld with fused type flux in this study was fairly less sensitive to delayed cracking than the manual weld with stick electrode, though the submerged arc weld with baked type flux in a previous study was more susceptible to delayed cracking than a manual weld. Angular distortion in a welded joint is detrimental to delayed cracking of the joint and is desirable to be kept minimum in an actual construction.
社団法人溶接学会の論文