Electroslag remelting slag system with low hydrogen permeability, preparation method and using method thereof

Abstract

The invention discloses an electroslag remelting slag system with low hydrogen permeability, and a preparation method and a using method thereof. The slag system is prepared from the following chemical compositions in percentage by weight: 45 to 50 percent of CaF2, 10 to 15 percent of CaO, 30 to 35 percent of Al2O3, 5 to 10 percent of SiO2, and 5 to 10 percent of MgO, wherein the MgO is adopted toreplace partial CaO. The preparation method is to crush the compositions into particles after melting, and bake the particles. The using method adopts pre-melting slag and argon protection to carry out electroslag remelting. Compared with the prior art, the slag system and the methods have the advantages that: the slag system has low hydrogen permeability, can effectively reduce the hydrogen content in steel in the remelting initial stage to ensure that the hydrogen content in the steel in the normal remelting stage is maintained at a lower level, and the hydrogen content in the remelted steel is less than 1.5ppm.

Description

technical field [0001] The present invention relates to the field of electroslag metallurgy, especially belongs to the electroslag remelting slag system. MgO is used to replace part of CaO, and the composition of the slag system is appropriately adjusted so that the slag system has low hydrogen permeability; at the same time, pre-melted slag and argon gas protection measures are adopted. To reduce the hydrogen content in steel after remelting. Background technique [0002] Since the birth of electroslag remelting technology, it has been an important means of producing special materials. In the electroslag remelting process, during the droplet formation stage at the electrode tip and the droplet dripping stage through the slag pool, the steel and slag are in full contact, and the non-metallic inclusions in the steel are absorbed by the slag. Under the cover of the slag pool, the liquid metal basically avoids re-oxidation. The rising slag pool forms a thin layer of slag shel...

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Problems solved by technology

[0009] The production of cold roll blanks generally adopts 40% CaF 2 -30%CaO-30%Al 2 o 3 The ternary slag system is used for electroslag remelting. Because the CaO component in the slag system is as high as 30%, the hydrogen content in the steel in the initial remelting period can reach more than 10ppm, and the hydrogen content in the steel in the normal remelting period is also as high as 5-7ppm. Long-term hydrogen expansion annealing treatment is required in the later stage, which not only occupies the production equipment, increases the production cost of the product, but also increases the production cycle of the product

[0010] After searching the patent literature, I found a patent related to electroslag remelting to prevent hydrogenation: the publication number is CN1078500. This patent mainly uses dry air protection to prevent hydrogenation in the electroslag remelting process, and has no special requirements for the slag system. The material can not be baked, because the electroslag remelting slag system CaO component mentioned in the patent is as high as 30%, and the slag material can not eliminate the influence of CaO on hydrogenation due to moisture absorption without baking.

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