A kind of preparation method of low-carbon low-silicon aluminum-killed steel composite purifying agent alloy

Abstract

The invention relates to a manufacturing method for low-carbon low-silicon aluminum and killed steel compounded alloy acting as purifying agent. The manufacturing method comprises the following stepsof: by adopting a wire-feeding remelting method, adding alkaline-earth metals to liquid ferroaluminum alloy through a wire feeder to prepare aluminum-based alkaline-earth composite alloy acting as purifying agent; in smelting, mixing an aluminum ingot and waste steel in a prepared charging material, adding the mixture to a heating furnace and smelting to form ferroaluminum alloy; subsequently feeding alkaline-earth metal wires through the wire feeder, wherein the alkaline-earth metal wires include a barium wire and a calcium wire, the wire feeding sequence is that the barium wire is fed firstly, the calcium wire is fed after the barium wire is molten, and the wire feeding speed is 1 m / s to 5m / s; after all wires are fed, uniformly stirring, deslagging and discharging, wherein the temperature of the liquid ferroaluminum alloy in a wire feeding process is controlled to be 20-50 DEG C higher than the melting point of the alloy; when the temperature is lower than the lower limit, the heating furnace is supplied with power according to 10% to 20% of load; when the temperature is higher than the upper limit, a power-off wire-feeding operation mode is adopted; pouring metal liquid into a cast iron ingot mold, cooling, solidifying and demolding, and crushing into an alloy block of a specified specification. According to the manufacturing method provided by the invention, the feeding speed of the alkaline-earth metals is controllable, and the yield of the alkaline-earth metals is high.

Description

technical field [0001] The invention relates to the technical field of steelmaking deoxidation and purification, in particular to a method for manufacturing a low-carbon, low-silicon, aluminum-killed steel composite purifying agent alloy. Background technique [0002] Because the cleanliness of molten steel seriously affects the quality of steel, the concept of clean steel (ultra-clean steel) has been proposed in recent years. The so-called cleanliness of steel includes two aspects: one is the content of non-metallic inclusions in steel; the other is the composition, shape, size and distribution of inclusions. Because aluminum can effectively reduce the oxygen in molten steel to a lower level, aluminum is generally used as a deoxidizer for molten steel, especially low-carbon, ultra-low-carbon, and low-silicon steels. However, after deoxidizing with aluminum, a large amount of aluminum oxide will be formed in the steel. Since the aluminum oxide with a high melting point is d...

AI Technical Summary

Problems solved by technology

Large loss of calcium, low efficiency, high cost of use, waste of resources, and pollution of the environment

[0004] Chinese patent CN200910010156.7 discloses a steel-making deoxidized aluminum-calcium-iron alloy, its chemical composition (weight%) is: 20%-70% of aluminum, 1%-40% of calcium, and the balance is one of iron or manganese Or two and unavoidable impurities, due to the addition of a certain amount of calcium, the shape of aluminum oxide and sulfide inclusions is changed to a certain extent, which reduces the burden of subsequent processing procedures, but its disadvantages are that the alloy The content of calcium element in the steel is limited, if it is too high, it will cause violent boiling and splashing combustion after the molten steel is put into it, the density of the alloy will decrease, and the alloy will float and burn seriously.

Because calcium is an active metal, the oxidation loss is huge, so it is impossible to produce high-grade ferroalloys. Generally, the calcium content can only reach single digits, and the alkaline earth elements contained in the alloy are single, and multi-element complementation cannot be achieved, so its use effect is restricted.