电渣重熔过程中熔渣成分变化的研究

Variation of the molten slag during the electroslag remelting process

在电渣重熔过程中,熔渣的成分经常会随时间推移发生变化,熔渣成分的变化会影响电渣重熔锭元素分布的均匀性,甚至影响电渣重熔工艺的顺行.本文从含氟渣系的挥发和渣壳形成两个方面出发,论述影响电渣重熔过程中熔渣成分变化的因素以及熔渣成分变化对电渣重熔锭中Al、Ti元素烧损的影响.结果表明:CaO会降低熔渣的失重率,SiO_2和Al_2O_3会提高熔渣的失重率;渣壳的非平衡凝固引起的组分偏析,会使高熔点相Ca_4Al_6F_2O_(12)(3CaO·3Al_2O_3·CaF_2)和Ca_(12)Al_(14)F_2O_(32)(11CaO·7Al_2O_3·CaF_2)析出,致使熔渣的成分发生变化.此外,在电渣重熔Inconel 718高温合金过程中,通过理论计算,得出渣系中加入6%～10%的TiO_2能够抑制熔渣成分变化,并降低合金中Al和Ti的烧损.

In process of the electroslag remelting,composition of the slag often changes with time.The change will affect the uniformity of the element distribution of the electroslag remelting ingot,and even affect the proceeding of the electroslag remelting process.In this paper,from the two aspects i.e.volatilization of the fluorine slag and formation of the slag shell,the factors affecting the composition of the slag in the electroslag remelting process and the influence of the slag composition change on loss of the Al and Ti elements in the electroslag remelting ingot were discussed.The results showed that CaO will reduce the weight loss ratio,while SiO 2 and Al 2O 3 will increase it.Segregation of the components formed by the non-equilibrium solidification of the slag shell will cause a precipitate of the high melting point phases.Such as Ca 4Al 6F 2O 12(3CaO·3Al 2O 3·CaF 2)and Ca 12 Al 14 F 2O 32(11CaO·7Al 2O 3·CaF 2)resulting in change of the composition in the slag.In addition,in the process of electroslag remelting for Inconel 718 superalloy,through the theoretical calculation,it is concluded that addition of 6%~10%TiO 2 in slag system can inhibit change of slag composition and reduce loss of Al and Ti in the alloy.