Process for casting hot air grate for blast furnace

Abstract

The invention relates to a process for casting a hot air grate for a blast furnace. The process is characterized in that: 1) in the process, the casting shrinkage factor of an outer shape and a core is 1.1 to 1.2 percent, side bottom circumferential injection water gaps, namely a straight water gap, a horizontal water gap, and an inner water gap are adopted, the thickness of the inner water gap is 6 to 8mm, and the section ratio of a sigma A straight water gap to a sigma A horizontal water gap to a sigma A inner water gap is (1.2-1.8):(2.0-3.0):1.0; 2) molten iron comprises the following chemical components in percentage by weight: 3.0 to 3.8 percent of C, 2.0 to 3.0 percent of Si, less than or equal to 1.0 percent of Mn, less than or equal to 0.07 percent of P, less than or equal to 0.08 percent of S, 0.5 to 1.5 percent of Cr, and the balance of Fe, and the sum of the weight percentage of all the components is 100 percent; and 3) casting temperature is 1,400 to 1,420 DEG C, and a mold is removed after heat is preserved for 20 to 24 hours. The process has the advantages that the appropriate casting shrinkage factor is selected aiming at the chemical components and casting conditions of molten iron casting, so the surface quality and dimensional tolerance of the hot wind grate for the blast furnace can meet the technical requirements.

Description

technical field [0001] The invention relates to the field of casting technology, in particular to a casting process of a blast furnace hot air grate. Background technique [0002] At present, most of the blast furnace hot air grates at home and abroad are plum-shaped holes, which are produced by casting method. Most of the materials are RTCr or RTCr2. The requirement is ±1mm, the center distance of the adjacent two holes of the grate is ±1mm for the upper plane, ±2mm for the lower plane, and the diameter of the round hole is ±1mm. In the current casting process, the surface is prone to slag inclusion defects. The casting shrinkage rate is selected according to the casting manual of 8-10‰. The dimensional tolerance of the castings is difficult to meet the requirements, and the dimensional accuracy of the castings cannot be guaranteed. As well as surface repair treatment, it reduces work efficiency and wastes materials. SUMMARY OF THE INVENTION [0003] The purpose of the ...

AI Technical Summary

Problems solved by technology

In the current casting process, slag inclusion defects are prone to appear on the surface, and the casting shrinkage rate is selected according to 8-10‰ in the casting manual. The dimensional tolerance of the casting is difficult to meet the requirements, and the dimensional accuracy of the casting cannot be guaranteed. A large amount of grinding is required after casting. And surface repair treatment, which reduces work efficiency and wastes materials

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