摘要:
针对河北某钢铁公司生产中出现60Si2Mn A钢材内裂率升高的问题,结合实际生产冶炼过程,对钢材内部裂纹缺陷的形貌特征、形成原因、影响因素及控制措施等方面进行了系统的研究,结果表明:钢中大颗粒夹杂物是导致60Si2Mn A钢材产生内部裂纹的主要因素。夹杂物种类为铝、镁、钙、硅复合氧化物。钢液中[Al]、[Ca]及精炼渣(MgO)含量偏高、钢包及大包套管耐材侵蚀严重是产生大颗粒夹杂物的主要原因。通过采用低铝硅铁代替普通硅铁、使用优质耐火材料,钢包空置时间 ≤ 1.5 h、每炉次更换一次大包套管、中间包使用双层覆盖剂等改进措施,使钢材内部裂纹发生率从0.53%降至0.11%。
Abstract:
In view of the high crack rate of 60Si2MnA steel,a systematic research on the steel crack's shape characteristics,formation causes,influencing factors,controlling measureshad been investigated,considering the practical producing and smelting process.It is found out that the internal cracks in60Si2MnA steel are mainly caused by large inclusions in the steel.The inclusions consist of compound complex of Al,Mg,Ca,and Si.The high contents of Al,Caand MgO in molten steel,together with the serious erosion of ladle and large casing refractory,are the main causes of large inclusions.By means of replacing ordinary silicon iron with low-Al silicon iron,using high quality refractory,limiting the empty time of ladle to less than 1.5 hours,replacing the large bundle casing for each furnace,and using double covering agent for tundish,the internal crack rate can be reduced from 0.53% to 0.11%.
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