Compound coate with with powder core and its making process

Abstract

The present invention is compound coated wire with powder core for treating molten iron or steel and its making process. The compound coated wire consists of steel belt coating and coated powder material, and features that the coated powder material includes inner powder containing metal element with boiling temperature lower than that of the metal liquid to be treated and an outer powder layer containing functional elements with boiling temperature higher than that of the metal liquid to be treated. The making process is one three-step material distribution process completed in a coated wire machine. The present invention has the advantages of lowered evaporation amount and utilization rate of the inner powder.

Description

technical field [0001] The invention relates to a composite powder-core cored wire for processing molten steel or molten iron and a manufacturing method thereof. Background technique [0002] At present, the known cored wires are all made of steel strips and powder wrapped in the steel strips, see figure 1 , and then feed it to the bottom of the processing ladle with the wire feeder to react with molten iron or molten steel, so as to achieve the purpose of improving the utilization or absorption rate of the fed elements in molten iron or molten steel. [0003] When the powder of the fed cored wire contains substances whose vaporization point is lower than the temperature of the molten metal it handles (hereinafter referred to as low vaporization point substances), such as: the powder fed into molten iron contains magnesium powder or magnesium alloy Powdered cored wire is used for desulfurization and spheroidization treatment of molten iron. When ...

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Problems solved by technology

[0006] 2) When silicon-calcium cored wire or silicon-barium-calcium cored wire is added to molten steel, although the melting point of calcium is increased when calcium exists in an alloy state, it is impossible to change the vaporization point of calcium. Therefore, feeding When feeding silicon-calcium wire or silicon-barium-calcium wire, there is also the phenomenon of early vaporization of calcium similar to that when feeding calcium-iron wire

[0007] 3) Due to the above reasons, using the current purified magnesium powder and alloy powder or metal powder to mix the cored wire or silicon-magnesium alloy powder as the core agent, the reaction is extremely intense when the wire is fed in the steel , the efficiency of magnesium is extremely low, which is greatly restricted in practical application, which sets obstacles to the industrial application of adding magnesium to steel to produce pure steel or high-purity steel

[0013] At present, the research direction of the production of pure steel and high-purity steel in the world is magnesium addition treatment. The pure steel treated with pure magnesium can reduce the number of oxide inclusions in the steel, but more importantly, the size of oxide inclusions is only 3 ~4um, and spherical, dispersed in the steel, the sulfide inclusions become composite inclusions, the size is significantly reduced, the isotropy of the steel after rolling is good, but the problem of adding magnesium to the steel has not been solved, and unable to implement

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