42CrMo钢大尺寸夹杂物的来源与控制  

Source and control of large-size inclusions in 42CrMo steel

作　　者：印传磊 翟万里[1,2] 蒋栋初 惠增杰 马庆丰 张益民 YIN Chuan-lei;ZHAI Wan-li;JANG Dong-chu;HUI Zeng-jie;MA Qing-feng;ZHANG Yi-min(Technology Center,Huaigang Special Steel Co.,Ltd.,Jiangsu Shagang Group,Huai′an 223002,Jiangsu,China;Key Laboratory of Special Steel New Materials for Rail Traffic of Jiangsu Province,Huai′an 223002,Jiangsu,China;Steelmaking Works,Huaigang Special Steel Co.,Ltd.,Jiangsu Shagang Group,Huai′an 223002,Jiangsu,China;School of Materials and Engineering,Jiangsu University of Technology,Changzhou 213001,Jiangsu,China)

机构地区：[1]江苏沙钢集团淮钢特钢股份有限公司技术中心,江苏淮安223002 [2]江苏省轨道交通用特殊钢新材料重点实验室,江苏淮安223002 [3]江苏沙钢集团淮钢特钢股份有限公司炼钢厂,江苏淮安223002 [4]江苏理工学院材料工程学院,江苏常州213001

出　　处：《中国冶金》2021年第1期36-41,共6页China Metallurgy

摘　　要：针对42CrMo合结钢轧材超声波探伤合格率低的问题,利用扫描电镜等设备对探伤不合样品进行分析,发现探伤不合样品中有直径为100μm左右的球形夹杂物或者尺寸为1 000μm左右的长条形夹杂物。通过钢液内生夹杂和生产过程接触的原辅料的分析比对,认为大尺寸夹杂物主要由于外来夹杂进入钢液中,最终造成轧材探伤合格率低。通过增加硅钙线用量、钢包浇铸后期不下渣、浸入式水口侵蚀速率小于1.5 mm/h、结晶器液位波动不大于±3 mm和恒定拉速浇铸等控制方式,减少了钢中外来大尺寸夹杂,提高了钢液洁净度,使探伤合格率提高到97.5%以上。For the problem of low pass rate of ultrasonic flaw detection of 42 CrMo bonded steel rolling materials, the unqualified sample for flaw detection was analyzed by SEM, etc. It was found that there were spherical inclusions with a diameter of about 100 μm or long bar inclusions with a size of about 1 000 μm in the unqualified samples. By comparing and analyzing the composition of small particle inclusions, subsidiary materials and the refractory materials, it was believed that large-size inclusions came from caused by exogenous inclusions entering in molten steel, which eventually resulted in the low pass rate of flaw detection of rolled products. By increasing the amount of calcium silicate wire, avoiding the slag of the ladle in casting process, using high quality submerged nozzle with erosion rate less than 1.5 mm/h, controlling the mold liquid level fluctuation no more than ±3 mm and applying constant casting speed, etc, it can effectively reduce large inclusions in steel, improve the cleanliness of molten steel, and increase the qualified rate of flaw detection to above 97.5%.

关 键 词：合结钢 探伤 大尺寸夹杂物 硅钙线 洁净度 

分 类 号：TF703[冶金工程—钢铁冶金]