Core cabling wire for steel melting and preparation thereof

Abstract

The invention discloses a cored-wire for making steel made by using waste slag and calcium slag of metal calcium produced by aluminothermy reduction method to replace reduced iron in the iron calcium cored-wire. The wire core components are as follows: 20 percent to 35 percent of metal calcium, 3 percent to 5 percent of metal magnesium, 60 percent and 75 percent of calcium slag and 2 percent to 4 percent of passive lime. The cored-wire is used for vacuum device treatment of ultra-low carbon, low nitrogen and low hydrogen steel and calcium treatment after aluminium-deoxidizing, can further reduce the contents of Al2O3 inclusions in steel, lightens casting nozzle clogging and reduces the smelting cost.

Description

1. Technical field [0001] The invention relates to metal refining, in particular to a cored wire used for refining outside a steelmaking furnace; the invention also relates to a preparation method of the cored wire. 2. Background technology [0002] At present, metal aluminum (or aluminum-iron alloy) is used as deoxidizer in converter smelting low-carbon aluminum-killed steel to remove free oxygen in steel. Aluminum is used as a deoxidizer, and the deoxidized product is Al 2 o 3 , it is extremely harmful to steelmaking. Thanks Al 2 o 3 High melting point (2050°C), fine solid phase in molten steel, poor mutual wettability, difficult to flocculate, grow and float to remove, and finally form Al in steel 2 o 3 Inclusions, which are non-plastic, will deteriorate the quality of the steel. At the same time, Al contained in molten steel 2 o 3 It will cause nodules in the continuous casting nozzle and cause the nozzle to be blocked. [0003] In order to remove Al from molte...

AI Technical Summary

Problems solved by technology

Due to the need to add oxygen to the molten steel during the vacuum treatment, the oxygen content of the treated molten steel is generally many times higher than that of the untreated one (the oxygen content can be increased from 30ppm to 600ppm). Al 2 o 3 The content is also much higher than that without treatment. Using the above-mentioned iron-calcium cored wire for calcium treatment of this molten steel has three disadvantages: first, the reduced iron in the cored wire is generally not completely reduced, and there is a certain amount of iron oxide in it. At the moment when it contacts molten steel together with calcium, metallic calcium is easy to reduce iron in iron oxide, so that part of calcium is lost on it, which reduces the utilization rate of calcium. To achieve the expected treatment effect, it is necessary to increase the feeding amount of calcium. , which increases the cost of steelmaking; the second is to only rely on the calcium in the cored wire to generate CaO and then combine with Al in molten steel 2 o 3 7Al 2 o 3 12CaO, then flocculate each other, grow up, float up into the slag, the speed is relatively slow, so that the Al in the molten steel 2 o 3 It takes a long time to be fully removed, and for the molten steel treated by the vacuum device, the time interval between deoxidation and pouring is limited to a short time, which cannot meet this time requirement, so the Al in molten steel 2 o 3 can not be fully removed; third, the price of reduced iron, the raw material used in this iron-calcium cored wire, is relatively high, and the cost of the cored wire is correspondingly high