Regular Article

Effect of slag-metal composite cored wire feeding on the cleanness of Al-containing steel

¹ College of Materials Science and Engineering, Hebei University of Engineering, Handan 056038, PR China
² Hebei Research Institute of Iron and Steel Technology, Shijiazhuang 050000, PR China
³ Advanced Manufacturing and Materials Centre, University of Warwick, Coventry CV4 7AL, UK

^* e-mail: zhaos418@hebeu.edu.cn

Received: 4 June 2018
Accepted: 21 August 2018

Abstract

The metal yield is low in traditional calcium treatment processing and secondary oxidation of molten steel can be serious. As such, it is of great interest to control the inclusions in steels by feeding the CaO-Al₂O₃-Ca composite cored wire as an alternative treatment where calcium is protected from sublimation until in contact with the melt. To analyse the effect of composite cored wire on cleanliness of the liquid steel, the evolution of inclusions in steel has been investigated. The initial composition of the calcium aluminate in composite cored wire was changed systematically, and reacted with Al-containing steel to study the effects of starting composition. It can be concluded that when the content of calcium aluminate in the core powder is 80 wt-% to 90 wt-% (the yield is 10%) or the content is 90 wt-% (the yield is 20%), the typical inclusions which have a lower melting point in the steel are spherical CaO-MnO-SiO₂-Al₂O₃, when the calcium aluminate content reaches to 70 wt-% (the yield is 10%) or the content reaches to 70 wt-% to 80 wt-% (the yield is 20%), CaO-MgO-Al₂O₃ or CaO-Al₂O₃ is more easily generated in the steel, Al₂O₃ is gradually reduced.