Mold powder capable of effectively controlling peritectic steel thick slab narrow face depression defect

Abstract

The invention relates to a mold powder capable of effectively controlling peritectic steel thick slab narrow face depression defect. The mold powder comprises the following elements by weight percent: 38.02 to 40.1 percent of Cao, 28.8 to 30.02 percent of SiO2, 9.9 to 10.5 percent of CaF2, 9.06 to 9.5 percent of Na2O, 1.55 to 1.93 percent of MgO, 1.5 to 1.93 percent of AL203, 0.01 to 0.037 percent of Li2O and 0.035 to 0.053 percent of MnO. The mold powder has good lubricating property and spreadability. Because of the high melting speed, the invention can complement the quick consumption of liquid slag in time; because of the high alkalinity, the invention has strong absorbing and mixing capability; and because of the proper viscosity and the reasonable crystallization temperature, the invention plays an important role in uniformity. When the mold powder is applied to the casting of peritectic steel thick slab, the slag entrapment defect caused by crystallizer liquid level fluctuation is reduced greatly, the heat transmission uniformity is improved greatly and the surface quality of casting blank is good.

Description

technical field

[0001] The invention belongs to the technical field of steelmaking-continuous casting, and in particular provides a new type of mold flux that can effectively control the concave defects of the narrow surface of the thick slab of peritectic steel, effectively controls the uniformity of the heat flow of the crystallizer, and is suitable for high-efficiency and stable thick-gauge slabs. The billet continuous casting process ensures the quality of the billet. Background technique

[0002] When C in continuous casting peritectic steel is 0.08-0.18%, peritectic reaction occurs during the solidification process. When C is in 0.10%, the conversion rate between the δ phase and γ phase of the primary shell near the meniscus at high temperature is 100%, with This irregular shrinkage is mainly concentrated in the range of 100mm below the meniscus of the mold, so the gap between the primary shell and the hot surface of the mold is the largest, and the heat flow of the mo...