Study On The Variation Of Oxygen And Inclusions In Electroslag Remelting Process

Electroslag remelting,as a special metallurgical method,has been gradually improved.It has a significant effect on the purity,especially the removal of sulfur,removal of non-metallic inclusions and improvement of inclusion distribution.In order to clarify this phenomenon and further study the change of inclusions during electroslag remelting,GCr15 bearing steel and 304 stainless steel were taken as the research objects to study the oxygen content,inclusion size and distribution of electroslag ingot in air,argon and different slag systems and variety.The main results are as follows:（1）When GCr15 bearing steel was remelted by electroslag in air,the oxygen content of electroslag ingot increased obviously,and the degree of oxygen increase can be reduced by changing the slag system.However,due to the influence of electric conductivity of slag system,electric parameters of remelting,air and other factors,it is found that reducing the content of Al₂O₃in slag has certain effect on reducing oxygen content in electroslag ingot,but the effect is not obvious.When 70%Ca F₂+30%Ca O was used for ESR,the inclusion size in ESR ingot was the smallest.（2）When GCr15 bearing steel was remelted with argon,the oxygen content in electroslag ingot decreased with the decrease of Al₂O₃content in slag system,and the oxygen content of electroslag ingot remelted with non-Al₂O₃slag system was the lowest.The diameter of inclusions in the electroslag ingot remelted in argon was smaller than that in the electroslag ingot remelted in air with the same slag system.（3）When 304 stainless steel was used as electrode,the content of Al₂O₃in slag system was 30%,20%and 0%respectively,and the corresponding oxygen content was46.85ppm,29.65ppm and 6.3ppm.It is proved that there is a corresponding relationship between oxygen content and Al₂O₃content in electroslag ingot.And the higher the oxygen content in the electrode,the better the deoxidization effect of electroslag remelting.The diameter of inclusions in ESR ingot with the lowest oxygen content was the smallest,the maximum diameter was only 4.72μm,and the average diameter was3.84μm.（4）The influence of oxygen in the air on the oxygen content in electroslag ingot could be basically avoided by using argon shielded electroslag remelting.The experimental results showed that in Ca F₂-Al₂O₃-Ca O slag system,the content of Al₂O₃in slag determines the oxygen content in electroslag ingot.The higher the content of Al₂O₃,the higher the oxygen content in electroslag ingot.Conversely,the oxygen content in electroslag ingot would decrease obviously.The reason of oxygen increase in electroslag ingot was that the oxygen content increases after the decomposition of Al₂O₃in the slag.