A kind of mold powder for peritectic steel slab continuous casting and its formula

Abstract

The invention relates to a mold mold powder for continuous casting of peritectic steel slabs. Its physical performance parameters are melting point of 1100°C to 1160°C, water content of 0.16%, viscosity of 0.1 Pa·s, its formula components and its weight Ratio is: SiO 2 : 25.45~31.45, Al 2 o 3 : 2.41~5.41, CaO: 37.73~43.73, MgO: 0.5~1.5, Na 2 O: 9.97~10.97, T.C: 2.71~4.31, F ‑ : 11.17~11.97, R: 1.37~1.49. Reduce the viscosity and melting point of the mold slag, improve the lubrication effect of the mold slag, and increase the melting rate of the mold slag; at the same time, the alkalinity of the mold slag increases, which increases the crystallization ratio in the mold slag liquid slag, slows down the heat transfer of the mold, and solves the problem of packaging Fluctuation of the liquid level in the crystal steel production process improves the casting speed of the peritectic series steel. After solving the problem of the liquid level fluctuation of the peritectic steel, the maximum casting speed of the actual medium-thick plate caster peritectic steel production can be controlled at 1.40m / min.

Description

technical field [0001] The invention belongs to the technical field of continuous casting and pouring steel, and relates to a mold mold powder for continuous casting of peritectic steel slabs and a formula thereof. Background technique [0002] When pouring steel with a carbon content of 0.08%-0.16%, the peritectic reaction occurs during the liquid-solid phase transition of the slab during solidification: δ+L→γ, and the density of face-centered cubic δ ferrite is greater than that of body-centered cubic γ Austenite, the transformation process is accompanied by 0.38% linear shrinkage, which produces a large phase transformation stress, which makes the thickness of the solidified shell uneven, which easily leads to the following problems: 1. A transverse temperature gradient is generated, which leads to longitudinal cracks on the surface of the billet; 2. .When the slab is pulled out of the fan-shaped section and passes through the rollers, it repeatedly bulges, resulting in f...

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Problems solved by technology

[0002] When pouring steel with a carbon content of 0.08%-0.16%, the peritectic reaction occurs during the liquid-solid phase transition of the slab during solidification: δ+L→γ, and the density of face-centered cubic δ ferrite is greater than that of body-centered cubic γ Austenite, the transformation process is accompanied by 0.38% linear shrinkage, which produces a large phase transformation stress, which makes the thickness of the solidified shell uneven, which easily leads to the following problems: 1. A transverse temperature gradient is generated, which leads to longitudinal cracks on the surface of the billet; 2. .When the slab is pulled out of the fan-shaped section and passes through the rollers, it repeatedly bulges, resulting in fluctuations in the liquid level of the crystallizer. Continuous casting can only reduce the casting speed and cast steel, which affects production, and easily causes slag inclusions or cracks in the slab, affecting quality.

[0004] Referring to Table 1 and Table 2, it can be known that the melting point and viscosity of the existing mold slag are too high, which affects the normal melting of the mold slag, easily leads to poor slag discharge, and affects the heat transfer of the mold

At the same time, the alkalinity is low, and the proportion of crystalline phase in the liquid slag is small, which cannot effectively slow down the heat transfer, and easily leads to uneven growth of the peritectic billet shell, causing fluctuations in the liquid level of the crystallizer, resulting in quality defects and affecting production.

[0005] The application number is CN200710052174.2 A method for preventing the liquid level fluctuation of the continuous casting peritectic steel mold. It is recorded that the chemical composition of the new formula mold powder satisfies the weight %: 35%2 2 O2 o 3 - 2 O2 o 3 - It is obviously different, and its slab quality still has defects, and it cannot improve the casting speed of peritectic steel series steel grades

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