Preparation technology of nitrided ferrovanadium

Abstract

The invention discloses a preparation technology of nitrided ferrovanadium. According to the preparation technology, a pushed slab kiln is filled with nitrogen for protection, and the oxygen content inside and the oxygen content outside a sealed chamber of the pushed slab kiln are kept the same by washing with nitrogen; and then ferrovanadium with a granularity of 5 to 20mm is delivered into the sealed chamber continuously for nitridation so as to obtain the nitrided ferrovanadium, wherein input pressure of nitrogen is 0.2 to 0.4MPa, the pushed slab kiln is divided into a preheating zone with a temperature of 550 to 650 DEG C, a nitridation zone with a temperature of 1150 to 1250 DEG C, a temperature reducing zone with a temperature of 550 to 650 DEG C and a cooling zone with a temperature of 70 to 170 DEG C, and the raw material is processed for 300min, 600min, 300min and 200min in the four zones respectively. The nitride ferrovanadium prepared by the preparation technology is low in carbon content; apparent density reaches 6000 to 6300kg / m<3>, and is beneficial for addition in steel smelting process; and the input pressure of nitrogen is just 0.2 to 0.4MPa, and the preparation technology is realized under normal pressure.

Description

technical field [0001] The invention relates to a preparation process of ferrovanadium nitride. The invention belongs to the technical field of ferroalloy preparation. Background technique [0002] As a new type of additive, vanadium nitride can not only improve the comprehensive mechanical properties of steel, but also make the steel have good weldability, and can eliminate the extension of inclusions. The effect is especially pronounced in steel. [0003] Vanadium-nitrogen microalloying optimizes the precipitation of vanadium and refines ferrite grains, giving full play to the effects of grain refinement strengthening and precipitation strengthening, which greatly improves the strength and toughness of steel. Using vanadium-nitrogen micro-alloying, without adding other precious alloying elements, high-strength steel of 400-600MPa level can be obtained under hot-rolled conditions. It has been widely used in the development of products such as steel, CSP products and H-sh...

AI Technical Summary

Problems solved by technology

[0009] 1. The vanadium nitrogen alloy is prepared by nitriding after carbon reduction of vanadium oxide. The production process of grinding, mixing and block making is complicated and the production efficiency is low. Due to the addition of carbon powder, the carbon content in the vanadium nitrogen alloy is relatively high. It is about 5-6%. In addition, the density of the vanadium-nitrogen alloy produced is relatively small, generally 3000kg / m 3 It is not easy to add into molten steel during the smelting process, which is not conducive to the absorption of alloy elements, especially the absorption rate of nitrogen is generally only 60-75%

[0010] 2. The vanadium-nitrogen alloy is prepared by using vanadium iron grinding and briquetting nitriding process. The vanadium iron needs to be ground into a fine powder of about 100 meshes, which is difficult to operate and has low production efficiency, and wears quickly on abrasive equipment.

[0011] 3. The preparation of vanadium-nitrogen alloy by combustion method needs to be carried out in a high-pressure container, the production is not continuous enough, and the production efficiency is low. In addition, when the vanadium content is lower than 53%, it cannot automatically react, and 80% ferrovanadium is needed as a raw material to promote the reaction to proceed in the positive direction. High raw material cost

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