Factors analysis and improvement measures of piling up of cold heading wire rods caused by inclusions
SHI Yan-qiu1,CHEN Xiao-hui1,WANG Yue-cong2,WANG Yu-gang1
(1. The First Steelmaking Plant of HBIS Group Hansteel Company, Handan 056015, Hebei, China 2. Hanbao Ironmaking Plant of HBIS Group Hansteel Company, Handan 056015, Hebei, China)
Abstract:Based on the test results of compositions of piling inclusions and tundish nozzle nodulation, through analysis of the distribution rule of piling heat and inclusion balance calculation in steel making process, it is found that the causes of piling up of cold heading steel wire are excessive Al2O3 inclusions in steel making process, inadequate calcium treatment of refining, and calcium-aluminate and magnesia-alumina spinel etc. solid inclusions accumulating in tundish nozzles and falling into molten steel. Therefore it is needed to take preventive measures corresponding to those factors. Through the measures such as reducing final oxygen content of converter, normalizing the operation of bottom blowing argon of LF refining, controlling Al content in steel making process and extending soft blowing time of refining, etc, the amount of tundish nozzle nodulation reduces obviously and the numbers of piling which is caused by inclusions in steel making process reduce from the original more than 10 times/month down to less than 4 times/month.