20SiMn轧辊UT缺陷原因分析

Analysis of UT Defects Causes in 20SiMn Roller

在20SiMn材质轧辊UT超声探伤时发现存在内部缺陷,解剖此轧辊后采用MT磁粉探伤、成分分析、低倍酸蚀、金相分析等方法,对形成内部缺陷的原因进行了分析。结果表明:该轧辊氢含量超标,存在的内部缺陷为白点裂纹。建议优化冶炼工艺,采用真空炉冶炼钢锭,等温退火处理产品,以充分扩氢,避免出现白点缺陷。

Internal defects was found in 20SiMn roller during UT flaw detection.The roller was dissected,and the causes of internal defects were analyzed by MT flaw detection,composition analysis,low power acid etching,metallographic analysis and so on.The results show that,the hydrogen content of the roll exceeds the standard and the internal defect is white spot crack.It is suggested to optimize the smelting process,to use vacuum furnace to smelt steel ingot,and to treat products by isothermal annealing,so as to fully diffuse hydrogen and avoid white spot defects.