【摘要】 针对用户使用Q345B中厚板产品时出现成型裂纹、冷弯裂纹现象,进行了成分分析、扫描电镜分析。结果显示:钢中硫、磷、氮含量超标且波动较大,引起了冷脆、显微缺陷、蓝脆缺陷。扫描电镜观察,钢板边部存在显微裂纹,大量条带状组织和大型硫化物,引起基体组织大量存在拉长夹杂与显微分层缺陷,导致钢板冷弯时边部产生裂纹。更多还原

【Abstract】 To solve the defects of forming cracks and roll forming cracks in use of customers,composition analysis and SEManalysis are conducted for the Q345 B plate. It is showed that the contents of sulfur,phosphors,and nitrogen in steel are over the standard and have large fluctuation,and that causes cold shortness,micro defects and blue brittleness. In viewof SEM,there are obvious micro cracks,large quantity of banded structure and large- scale sulfide at edge of steel plate,and those cause elongated inclusion and micro layering defect in matrix structure,and at last cracks brought about in roll forming of steel plate.更多还原