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近年来,我国大型火力发电厂的锅炉汽包集中降水管,插入式焊接角焊缝相继发现裂缝等严重缺陷.对于这些缺陷的产生,论点不一.从现有解剖的几台5万千瓦机组220T/H炉集中降水管角焊缝情况来看,其缺陷不外乎沿焊缝纵向裂纹、K型坡口中部未焊透、大面积夹渣气孔等,这些缺陷的产生大都是焊接工艺不当及操作本身造成的.由于结构本身拘束度大、综合应力高,运行中缺陷有可能发展,焊接缺陷为诱发缺陷,在综合应力下扩展成裂缝.
In recent years, serious defects such as cracks and other serious defects have been found in the centralized boiler pipes and plug-in fillet welds of large-scale thermal power plants of boilers in China, and the disagreements have been made on these defects.From the existing dissection of several 50,000-MW units 220T / H furnace focus on precipitation angle fillet weld situation, the defect is no more than along the longitudinal weld cracks, K-shaped groove in the middle of incomplete penetration, large slag hole, etc., these defects are mostly improper welding process And the operation itself caused by the structure itself, the degree of restraint, the overall stress is high, the possible development of defects in the welding defects as induced defects, under the comprehensive stress to expand into cracks.