摘要
Q345D钢结构梁腹板对接接头热影响区出现了长约100mm的裂纹。采用金相方法观察了接头热影响区和母材的组织以及裂纹的宏观形貌,采用扫描电镜观察了裂纹的微观形貌以及对微区的化学成分分析。分析结果表明,焊接接头热影响区没有形成淬硬组织。裂纹两侧出现了一定宽度的脱碳层,脱碳层内部出现了二次氧化产物。该裂纹并不是焊接过程产生的裂纹,而是钢坯轧制以前其表面已存在微裂纹所致。
There was a crack, about 100mm long, in the heat affected zone （HAZ） of Q345D steel butt joint. The metallurgical structure of HAZ and matrix metal, along with pattern of the crack were observed using metallographic analysis. Scanning electronic microscope was used to analyze the microscopic shape of the crack and micro-area chemical composition. The results show that HAZ doesn＇t form the quench-hardening structure. Decarburized layer appears in the two sides of the crack. There is some secondary oxide existing in the decarburized layer. The flaw isn＇t the hot crack or cold crack resulted from welding. Microcrack has initiated early in the surface of billet steel, then the crack appears after welding.
出处
《理化检验（物理分册）》
CAS
2006年第8期416-418,共3页
Physical Testing and Chemical Analysis(Part A:Physical Testing)
