Inclusion modification in Al-killed valve spring steel by Na2CO3 addition. (28th May 2018)

• Record Type: Journal Article
• Authors: Chen, Liangjun; Chen, Weiqing; Yan, Wei; Peng, Hongbing; Yang, Yindong; McLean, Alexander
• Is Part Of: Ironmaking & steelmaking. Volume 45:Number 5(2018)
• Page Start: 397
• Page End: 405
• Publication Date: 2018-05-28
• Subjects: Inclusion modification -- Al-killed valve spring steel -- Na2CO3 addition -- Na2O-containing inclusions; Iron industry and trade -- Periodicals; Steel industry and trade -- Periodicals; 669.1
• DOI: 10.1080/03019233.2018.1482818
• Languages: English
• ISSNs: 0301-9233

Abstract

ABSTRACT: Hard inclusions with high melting temperatures such as Al2 O3 (2054°C) and MgO·Al2 O3 (2135°C) generate nozzle blockage problems during continuous casting of Al-killed valve spring steel and are very detrimental with respect to fatigue properties. In the present paper, inclusion modification in Al-killed valve spring steel by Na2 CO3 addition was investigated in the laboratory using a graphite tube resistance furnace. The results show that inclusions with high melting temperature can be successfully modified into Na2 O-containing inclusions with lower melting temperatures by the addition of Na2 CO3 . The effectiveness of inclusion modification can be enhanced by increasing the Na2 CO3 addition and/or decreasing the amount of Al. This suggests that Na2 CO3 addition could possibly be a substitute for Ca treatment as a method for preventing nozzle blockage during continuous casting of Al-killed steel.