连铸1Cr18Ni9Ti不锈钢大型夹杂物的研究

THE STUDY FOR LARGE INCLUSIONS OF STAINLESS STEEL (1Crl8Ni9Ti) DURING CONTINUOUS CASTING

报导了1Cr18Ni9Ti不锈钢的连铸工艺制度及铸坯中大型夹杂物的形貌、来源及分布,以及对轧材质量的影响。通过显微观察,发现铸坯中的大型夹杂物多为TiN加球形卷渣。X—射线结构分析、电子探针微区测试证实了球形卷渣主要来自保护渣。经理论计算证实:保护渣中的SiO_2不能将TiN转化成TiO_2。提出了降低连铸坯中大型夹杂物的措施。

This paper presents the process of stainless steel ( 1Crl8Ni9Ti) in continuous casting,the components and their shapes,origins and distributions of the large inclusions existing in the steel,as well as the influence on its quality. By the observation through a microscope,the structural analysis adopting x-ray examinating instrument and the measunement for the microzone of billet employing the electronic probe.it has been found that the large inclusions of continuous billet mainly originate from the slag-sweeping of the tundisy and mold. There are mostly spherical-slag in addition to Ti(C.N) in the inclusions. The calculations in theory point out that the siO2in the slag can' t change Ti(C,N) into TiO2,however,it can assimilate with Ti(C.N). The large inclusions affect the quality of the steel plate and tube greatly. As a result,this paper proposes the measures of reducing the large inclusions in the steel.