Ferrotitanium with low carbon, low silicon, and preparation technique

Abstract

This invention relates to a process for preparing low-C and low-Si Ti-Fe alloy, which mainly comprises: Ti 45-55 wt.%, Al 8-12 wt.%, Si below 1.5 wt.%, C 0.02-0.05 wt.%, P below 0.04 wt.%, S below 0.03 wt.%, Cu 0.05-0.1 wt.%, and Fe. The Ti-Fe alloy is prepared from Ti concentrate and rutile by smelting with aluminothermic method. The process comprises: (1) selecting the raw materials, and baking; (2) mixing main materials with igniting agent according to a certain weight ratio; (3) placing the base materials containing the igniting agent and part of the main materials into a smelting furnace, igniting the igniting agent, and adding the rest main materials after all base materials are molten; (4) adding lime powder as a retarder of residue surface, and discharging; (5) cooling, finishing and sieving. The method can lower the smelting cost of Ti alloy, and increase the utility of Ti.

Description

technical field [0001] The invention relates to the technical field of ferroalloys, in particular to a low-carbon and low-silicon ferro-titanium and a preparation process thereof. Background technique [0002] With the development of various steelmaking and refining technologies, people have been able to control the harmful elements in steel relatively easily, thereby improving the performance of steel grades to meet the needs of different manufacturing industries. Therefore, the iron and steel industry has also put forward high-purity requirements for ferroalloys used in steelmaking. It is hoped that the impurity elements contained in ferroalloys put into molten steel should be as low as possible to avoid secondary pollution to molten steel. [0003] As we all know, high-elongation deep-drawing thin iron plates use titanium as the alloying agent for steel, and are generally obtained by adding ferro-titanium into the molten steel refining furnace. Therefore, it requires tha...

AI Technical Summary

Problems solved by technology

However, it is still limited by waste titanium resources. When smelting steel, the effects of deoxidizing molten steel, controlling the size of primary grains of steel in the austenitic state, and benefiting the utilization of valuable element titanium are not very obvious. The smelted steel is not ideal in terms of anti-aging, plasticity, atmospheric corrosion resistance and good machinability

[0004] "Low-silicon ferro-titanium and its preparation method" disclosed in Chinese Patent Publication No. CN1446932 mainly introduces a low-silicon ferro-titanium containing 35-75% by weight of titanium, which is made of titanium concentrate and titanium waste. The raw material is the smelting method combining thermite method and remelting, or the low-silicon ferro-titanium obtained by remelting scrap steel and pure titanium in an open intermediate frequency furnace. Combining the melting method, the preparation method is simple and reliable, with less investment and lower cost, and the impurity content in the finished product is low, which is beneficial to the existence and control of trace elements, but the disadvantage is that the titanium and aluminum in the low-silicon ferro-titanium disclosed in this invention The content range of ferro-titanium is wide, but in fact, the difference in the amount of elements contained in it has a great influence on the performance and cost of ferro-titanium. Big

For example: a 70% ferrotitanium containing 70% titanium by weight, 70 ferrotitan has always been favored by users for its high titanium content and low content of impurity elements, but there are problems with 70 ferrotitan at the same time: first, the specific gravity is small, It is not easy to sink in the molten steel, so the yield of the main element titanium is slightly low, and the second is that the content of trace elements such as carbon and copper in the 70 ferro-titanium also has a certain degree of re-pollution to the molten steel; another example: a Ferro-titanium contains 3-5% by weight of aluminum and 0.4-0.5% by weight of silicon. The lower content of aluminum and silicon cannot fully exert the higher activity of aluminum and silicon than titanium, and also reduces the utilization rate of titanium. For another example, the sales price of 70 ferro-titanium is about 2000 yuan / grade, and the sales price of 40 ferro-titanium is about 600 yuan / grade, and the price difference is 3.2 times. It can be seen that the use of ferro-titanium with different components will also cause differences in steel alloys. smelting cost