散货轮甲板角焊缝失效原因分析

Analysis on Cracking in Fillet Weld of Bulk Carrier Deck

利用无损探伤、光学显微镜、扫描电镜和EDS能谱仪等检测仪器,分析了开裂的甲板角焊缝的宏观形貌、显微组织、断口形貌及化学成分。分析结果显示:甲板角焊缝裂纹断面无金属光泽,伴随有高温氧化色,且内部有较多夹渣;在裂纹断面发现大量淤泥状液态薄膜,液态薄膜中富集低熔点的硫化物。因此该裂纹属于典型的热裂纹。焊接工艺实施不当,是导致该角焊缝产生裂纹的主要原因。

The macro and micro structure,fracture morphology and chemical composition of the cracked deck fillet weld were analyzed by means of non-destructive testing,optical microscope,scanning electron microscope and EDS energy spectrometer.Results showed that the crack section of deck fillet weld has no metal lust-er,accompanied by high temperature oxidation color,and there are more slag inclusions inside;a large num-ber of muddy liquid films are found on the crack section,and low melting point sulfides are enriched in it.Therefore,it is a typical hot crack.Improper implementation of the welding process is the main reason for the cracks in the fillet weld.