Smelting method of low-density stainless steel

Abstract

The invention discloses a smelting method of low-density stainless steel, wherein the smelting method comprises the following steps: (1) adding molten iron into a converter, and blowing oxygen to decarburize; (2) adding high-carbon ferromanganese and high-carbon ferrochrome in the oxidation period of the converter; (3) in the reduction period of the converter, adopting silicon-aluminum composite deoxidation, enabling the total oxygen content in the steel to be lower than 70 ppm, controlling the mass fraction of generated reduction furnace slag components to be 1<=(CaO+MgO) / (SiO2+Al2O3)<=2, 5%<=CaF2<=10%, and FeO+MnO+Cr2O3<=3%, and thus obtaining decarburized molten steel; and (4) adopting an intermediate frequency furnace for a melting aluminum alloy to form molten aluminum liquid, mixing the decarburized molten steel obtained in the step (2) and the molten aluminum liquid into a steel ladle, and thus obtaining the low-density stainless steel. Reasonable components of the reduction furnace slag are controlled in the converter smelting process, and silicon-aluminum composite deoxidation is used according to the design requirements of the reduction furnace slag, so that the stability of the aluminum content in the molten steel after aluminum alloying is ensured, and the reaction between aluminum and the reduction furnace slag is inhibited.

Description

Technical field [0001] The present invention relates to stainless steel smelting processes, and more particularly to a smelting method of low density stainless steel. Background technique [0002] Low-density stainless steel is used as one of the main alloy components by adding light element aluminum, which reduces the density of steel, so that the density of steel is more than 15% more than conventional stainless steel density, reaching 6.3 ~ 6.6 g / cm. 3 At the same time, the strength to 1 GPa of steel is also improved. Studies have shown that the use of low-density stainless steel vehicles can reduce the weight by 10%, and fuel consumption can be reduced by 6% to 8%, so low-density stainless steel has broad application prospects in automobiles, ships and aerospace. [0003] As a new research direction in physical metallurgy and alloy design, low-density steel research is full of opportunities and faces challenges. Among them, in the low-density stainless steel smelting proces...

AI Technical Summary

Problems solved by technology

[0004] 1. The addition of a large amount of aluminum alloy can easily lead to insufficient heat in the smelting process

[0005] 2. Due to the high aluminum content in the low-density stainless steel molten steel, the unreasonable composition of the reducing slag will easily lead to continuous burning of aluminum, which will further affect the stability of the aluminum content

[0006] 3. Since the density of aluminum alloy (2.702 g / cm³) is much lower than that of steel (7.75 g / cm³), after adding a large amount of aluminum alloy, it is difficult to quickly realize the homogenization of molten steel and aluminum alloy. Floating on the surface of molten steel, it is easy to cause falsely high aluminum content during sampling, and insufficient aluminum content in the finished product after subsequent soft blowing and mixing