Premelting slag for RH vacuum treatment deep desulfurization of ultra low carbon steel

Abstract

The RH vacuum treatment deep desulfurization premelting slag for ultra-low-carbon steel comprises: 48~56% CaO, 33~43% Al2O3, 0.2~5.0% MgO, 2.5~6.0% SiO2ú¼TiO2íœ1.9, Cíœ0.05 and impurity, and is prepared by electric melting the material of super 60-65% limestone and 35-40% Al2O3 powder (Al-content more than 96%). This invention improves desulfurization capacity, produces Ca(AlO2)2 convenient to preserving, and has little corrosion to RH groove.

Description

(1) Technical field [0001] The invention relates to a steelmaking vacuum refining technology, in particular to a RH vacuum treatment deep desulfurization pre-melting slag for ultra-low carbon steel and a preparation method thereof. (2) Background technology [0002] Chinese patent 98101510.7 discloses an aluminum-containing pre-melted slag, its preparation method, and a molten steel desulfurizer and purifier containing the slag. In this invention, the aluminum-containing slag is put into a metallurgical furnace, heated to melt the aluminum-containing slag, and then AlF is added 3 , CaF 2 , CaCl 2 or AlCl 3 Any one or more of them, continue heating, when the melt temperature exceeds 1450 °C, add SiO 2 and MgO slag adjusting agent, adjust slag according to the final slag composition; the composition of the obtained aluminum-containing pre-melted slag is (weight%): metal Al 12~15%, Al 2 o 3 65~75%, SiO 2 2~10%, MgO 2 ~6%, AlF 3 or CaF 2 or CaCl 2 or AlCl 3 Any one...

AI Technical Summary

Problems solved by technology

The aluminum-containing pre-melted slag of this patent does not include lime pre-melting. Due to the high melting point of lime, the pre-melted slag of this patent is simply mixed with lime before use, and the melting time in the refining process is long, which is not conducive to rapid Slagging reduces the desulfurization capacity, and the existing patented pre-slag contains fluorite (CaF 2 ), at the same time, there is no clear description of the carbon content, and it is not clear whether it can be used for desulfurization and refining of ultra-low carbon steel

The aluminum-containing pre-melted slag of this existing patent does not include lime pre-melted, and does not have desulfurization function. If it is mixed with lime, it is not conducive to preservation, because the slag containing lime will easily absorb moisture through mechanical mixing. It is not easy to preserve, not only will reduce the desulfurization ability, but also easily increase the hydrogen ((H)) of molten steel, affecting the quality of steel