Cr8Mo2VSi热轧扁钢超声波探伤缺陷分析及工艺改进  

Analysis on Defect of Hot Rolled Flat Steel Cr8Mo2VSi by Ultrasonic Testing and Process Improvement

作　　者：孙秀华[1] 王继红 祁勇 康爱军[1] 李鹏 燕云[1] Sun Xiuhua;Wang Jihong;Qi Yong;Kang Aijun;Li Peng;Yan Yun

机构地区：[1]抚顺特殊钢股份有限公司技术中心,辽宁抚顺113000 [2]抚顺特殊钢股份有限公司第一轧钢厂,辽宁抚顺113000

出　　处：《模具制造》2020年第7期83-85,共3页Die & Mould Manufacture

摘　　要：通过酸蚀低倍和金相高倍检验,以及结合生产工艺分析,确定了Cr8Mo2VSi热轧小扁钢和大扁钢超声波探伤缺陷为微裂纹,小扁钢为过热型裂纹,是由于钢坯出炉速度慢导致加热时间长而过热;大扁钢为撕裂型裂纹,是由于钢坯出炉速度快导致加热时间短而芯部没有透烧.根据分析结果,改进钢坯加热工艺,小扁钢的钢坯加热温度比原来降低10℃,出炉速度为2~4min/支,大扁钢的钢坯加热温度与原来相同,出炉速度为4~6min/支.通过生产验证,探伤合格率小扁钢由原来的84.6%提高到100%,大扁钢由原来的52.4%提高到95%.Through acid etching macro,metallographie micro inspections,as well as the production process analysis,it was confirmed that defects of hot rolled small flat and large flat steel Cr8Mo2VSi detected by ultrasonic testing were micro cracks.The micro crack of small flat was caused by overheating due to slow discharging speed and long heating time,and the micro crack of large flat was caused by insufficient heating due to fast discharging speed and short heating time.Therefore,heating processes of billets need to be improved.With 2~4 min/piece of discharging speed,heating temperature of billet for small flat is 10°C lower than before.As for large flat,its heating temperature stays the same with 4~6 min/piece of discharging speed.The results show that UT pass rate of small flat increases from 84.6%to 100%and that of large flat from 52.4%to 95%.

关 键 词：Cr8Mo2VSi钢 超声波探伤 微裂纹 工艺改进 

分 类 号：TG162[金属学及工艺—热处理] TG142[金属学及工艺—金属学]