Effect of Refining Process on Purity of Pipe-Line Steel

The effects of LD-LF-CC and LD-ANS-OB-CC refining processes on the purity of pipe-line steel were investigated.The contents of oxygen,nitrogen and inclusions during refining were studied quantitatively by metallographic and chemical analysis.The results indicate that the molten steels refined by LF and ANS-OB are of same cleanness,but the product cost can be reduced by use of LD-ANS-OB-CC.Blowing argon is a main factor for removing inclusions in refining process.The contents of oxygen,nitrogen and inclusions can be reduced to a minimum,when the refining time reaches 40 minutes.