C-Mn类大型锻件试块缺陷的检测分析

摘要

针对我公司生产的某一C-Mn类大型锻件产品经锻造及正、回火处理之后切取试块时发现的1处记录性缺陷，采用低倍酸洗、宏观断口体视镜观察及扫面电镜能谱分析等手段，并结合对冶炼过程中精炼包耐火砖使用状况的综合分析，最终确定钢水浇注时，精炼包包壁上耐火砖剥落，导致MnS、 TiN等杂质化合物富集并偏析，是引起试块探伤缺陷的主要原因。%An unacceptable defect was found out in the test sample cut from a C-Mn large product forging that was subject to forging operation, normalizing and tempering heat treatments. In order to find out the cause, the test sample was tested by the means of low-acid pickling, microphotography stereo microscope, scanning electron microscope (SEM) and energy disperse spectroscopy (EDS) . In addition, the condition of the firebricks in the refining ladle during steel melting was examined. It was concluded the peeling-off of the fire-bricks on the ladle wall caused the enrichment and segregation of MnS, TiN and other compounds to form the defect.