Based on the industrial production of non-oriented silicon steel,calcium treatment by CaSi wire feeding during the RH refining process was studied.The thermodynamics of CaS inclusion formation was analyzed,and the mor...Based on the industrial production of non-oriented silicon steel,calcium treatment by CaSi wire feeding during the RH refining process was studied.The thermodynamics of CaS inclusion formation was analyzed,and the morphology and the size distribution were observed.Furthermore,the change in inclusion characteristics after calcium treatment and the effect of calcium treatment on magnetic properties were discussed.The results show that the formation of MnS and AlN inclusions were restrained,and the aggregating,floating and removing of microinclusions after calcium treatment were effectively promoted.The cleanliness of liquid steel was obviously increased.The main type of inclusions was single phase of CaO,with some complex inclusions composed of CaO,SiO2 and MgO.No CaS inclusion was observed after an appropriate calcium treatment.The size of all inclusions was distributed in the range of 2-20 μm,and the number was about 1.8×105 /mm3.In addition,as an increasing amount of calcium was added,the core loss gradually decreased to a stable level,and the magnetic induction decreased quickly after a slow increase.The optimal calcium treatment mode depends on the chemical composition of steel.展开更多
In this paper,a kind of three-dimensional analysis technology for characterizing non-metallic inclusions in steel was clearly elaborated.It is an electron microscopy observation,namely the non-aqueous electrolysis ext...In this paper,a kind of three-dimensional analysis technology for characterizing non-metallic inclusions in steel was clearly elaborated.It is an electron microscopy observation,namely the non-aqueous electrolysis extraction method with a settled coulometer.In the research,the extraction effects of non-metallic inclusions in different electrolysis systems were studied,and it was concluded that alkalescent 2% TEA non-aqueous electrolyte was applicable for extracting most of non-metallic inclusion particles in steel.And then,in order to ensure the microscopic characterization and statistical calculation of inclusion particles,some electrolysis parameters should be confirmed,such as the size of the sample,control of the electrolysis mass,electric current,etc.Furthermore,for preventing the disturbance of carbides and presenting clear three-dimensional appearance by microscopic characterization,magnetic separation was utilized to separate the inclusion particles from carbides,which was useful for getting more veracious types,particle sizes and chemical composition of inclusions.Moreover,through calculation of quantity and particle size of inclusions in continuous determinate fields,the total quantity per unit volume or area and the particle size distribution of inclusions could be acquired by conversion with electrolysis loss.Besides,the comparison between this method and traditional quantitative metallography was also discussed,and finally,a conclusion was drawn that both of them have respectively applications in characterizing inclusions.展开更多
文摘Based on the industrial production of non-oriented silicon steel,calcium treatment by CaSi wire feeding during the RH refining process was studied.The thermodynamics of CaS inclusion formation was analyzed,and the morphology and the size distribution were observed.Furthermore,the change in inclusion characteristics after calcium treatment and the effect of calcium treatment on magnetic properties were discussed.The results show that the formation of MnS and AlN inclusions were restrained,and the aggregating,floating and removing of microinclusions after calcium treatment were effectively promoted.The cleanliness of liquid steel was obviously increased.The main type of inclusions was single phase of CaO,with some complex inclusions composed of CaO,SiO2 and MgO.No CaS inclusion was observed after an appropriate calcium treatment.The size of all inclusions was distributed in the range of 2-20 μm,and the number was about 1.8×105 /mm3.In addition,as an increasing amount of calcium was added,the core loss gradually decreased to a stable level,and the magnetic induction decreased quickly after a slow increase.The optimal calcium treatment mode depends on the chemical composition of steel.
文摘In this paper,a kind of three-dimensional analysis technology for characterizing non-metallic inclusions in steel was clearly elaborated.It is an electron microscopy observation,namely the non-aqueous electrolysis extraction method with a settled coulometer.In the research,the extraction effects of non-metallic inclusions in different electrolysis systems were studied,and it was concluded that alkalescent 2% TEA non-aqueous electrolyte was applicable for extracting most of non-metallic inclusion particles in steel.And then,in order to ensure the microscopic characterization and statistical calculation of inclusion particles,some electrolysis parameters should be confirmed,such as the size of the sample,control of the electrolysis mass,electric current,etc.Furthermore,for preventing the disturbance of carbides and presenting clear three-dimensional appearance by microscopic characterization,magnetic separation was utilized to separate the inclusion particles from carbides,which was useful for getting more veracious types,particle sizes and chemical composition of inclusions.Moreover,through calculation of quantity and particle size of inclusions in continuous determinate fields,the total quantity per unit volume or area and the particle size distribution of inclusions could be acquired by conversion with electrolysis loss.Besides,the comparison between this method and traditional quantitative metallography was also discussed,and finally,a conclusion was drawn that both of them have respectively applications in characterizing inclusions.
