Analysis and Controlling of Crack on 60Si2MnA Steel

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%.