阅读说明：本技术 一种镁合金熔炼的中碳钢坩埚表面处理除铁工艺 (Surface treatment iron removal process for medium carbon steel crucible for smelting magnesium alloys ) 是由 戴甲洪 蒋斌 杨青山 谢红梅 徐向俊 赵炎春 朱云虎 向超 彭程 于 2019-11-19 设计创作，主要内容包括：本发明公开了一种镁合金熔炼的中碳钢坩埚表面处理除铁工艺,包括以下步骤：S1：表面清理,取两个品质相同的中碳钢坩埚,并记为中碳钢坩埚A和中碳钢坩埚B,用200目砂纸分别将中碳钢坩埚A和中碳钢坩埚B的内表面的氧化皮打磨掉,然后用酒精清洗表面；S2：热镀,将中碳钢坩埚A放入电阻炉中,然后倒入预先熔化好的Mg-3wt.％Al-4wt.％Mn的镁合金,通过气体保护,在800℃下保温20min,在中碳钢坩埚A的内壁热镀上厚度8μm的Al-Mn化合物层,然后将镁熔体倒出。本发明中热镀Al-Mn化合物层后铁含量大大降低了,可以有效的阻碍了铁坩埚中的杂质元素Fe向镁熔体中扩散,提高了镁合金的纯度。(The invention discloses a surface treatment iron removal process for a medium carbon steel crucible for smelting magnesium alloys, which comprises the following steps of S1, cleaning the surface, taking two medium carbon steel crucibles with the same quality, marking as a medium carbon steel crucible A and a medium carbon steel crucible B, respectively polishing away oxide skins on the inner surfaces of the medium carbon steel crucible A and the medium carbon steel crucible B by 200-mesh abrasive paper, cleaning the surface by alcohol, S2, hot-dipping, putting the medium carbon steel crucible A into a resistance furnace, pouring magnesium alloy of Mg-3 wt.% and Al-4 wt.% which are pre-melted, preserving the temperature for 20min at 800 ℃ through gas protection, hot-plating an Al-Mn compound layer with the thickness of 8 mu m on the inner wall of the medium carbon steel crucible A, and pouring out a magnesium melt.)

1, kinds of magnesium alloy smelt medium carbon steel crucible surface treatment deferrization craft, characterized by, including the following steps:

s1: cleaning the surface, namely taking two medium carbon steel crucibles with the same quality, marking as a medium carbon steel crucible A and a medium carbon steel crucible B, respectively polishing away oxide skins on the inner surfaces of the medium carbon steel crucible A and the medium carbon steel crucible B by 200-mesh abrasive paper, and then cleaning the surface by using alcohol;

s2: hot-dip, putting the medium carbon steel crucible A into a resistance furnace, then pouring the magnesium alloy of Mg 3 wt.% Al 4 wt.% Mn which is melted in advance, preserving the heat for 20min at 800 ℃ under the protection of gas, hot-dip plating an Al-Mn compound layer with the thickness of 8 mu m on the inner wall of the medium carbon steel crucible A, and then pouring out the magnesium melt;

s3: smelting, namely respectively melting pure magnesium in a medium carbon steel crucible A and a medium carbon steel crucible B at 700 ℃, and naturally cooling the melt in the crucibles after heat preservation for 60 min;

s4: and (3) measuring Fe, namely sampling at the edge and the center of the pure magnesium ingot respectively, and measuring the Fe content in the sample by using an atomic emission spectrometer.

2. The process for removing iron from the surface of the medium carbon steel crucibles containing magnesium alloy smelted according to claim 1, wherein the protective gas in the step S2 is CO2+ SF 6.

Technical Field

The invention relates to the technical field of magnesium alloy smelting, in particular to a surface treatment iron removal process for a medium carbon steel crucible for smelting magnesium alloys.

Background

The magnesium alloy is used as the lightest engineering metal structure material in the current industrial application, has the advantages of small density, high specific strength specific rigidity, strong damping and vibration reduction capability, superior casting performance, good cutting processing performance, electromagnetic radiation shielding, easy recycling and the like, and has important application value and broad application prospect in the fields of automobiles, railway vehicles, 3C products, aerospace, national defense and military industry and the like.

In order to solve the above problems, in recent years, a great deal of research work has been done on alloying, heat treatment, grain refinement, deformation processes, etc., and important progress has been made, besides, the purity of magnesium alloy is which is the most important factor affecting the corrosion resistance of magnesium alloy, especially the content of harmful impurity elements such as Fe, Si, Ni, Cu, etc. in magnesium alloy, studies show that the presence of harmful impurity elements greatly reduces the quality of magnesium alloy ingots, which seriously affects the texture, corrosion resistance, mechanical properties and forming properties of magnesium alloy materials, and in these metal impurities of magnesium alloy, Fe is the most harmful impurity element, because the impurity element Fe is easily brought into magnesium melt through raw materials, melting tools, etc., the pure magnesium melt is the basic premise for obtaining high-quality magnesium alloy materials with good comprehensive properties, research and development of magnesium alloy purification technology, the effective reduction of the content of impurity element in cast blanks, the slow introduction of Fe, the impurity element in magnesium alloy, the melting process of Fe, the melting of magnesium alloy, the melting of iron, the melting alloy, the melting flux of magnesium alloy, the melting flux of Fe, the melting flux of magnesium alloy, the melting flux, the crucible, the melting flux of magnesium alloy, the melting flux, the flux.

Disclosure of Invention

The invention aims to solve the defects in the prior art, and provides a surface treatment iron removal process for a medium carbon steel crucible for smelting magnesium alloys.

In order to achieve the purpose, the invention adopts the following technical scheme:

the surface treatment iron removal process for the medium carbon steel crucible smelted by kinds of magnesium alloy comprises the following steps:

s1: cleaning the surface, namely taking two medium carbon steel crucibles with the same quality, marking as a medium carbon steel crucible A and a medium carbon steel crucible B, respectively polishing away oxide skins on the inner surfaces of the medium carbon steel crucible A and the medium carbon steel crucible B by 200-mesh abrasive paper, and then cleaning the surface by using alcohol;

s2: hot-dip, putting the medium carbon steel crucible A into a resistance furnace, then pouring the magnesium alloy of Mg 3 wt.% Al 4 wt.% Mn which is melted in advance, preserving the heat for 20min at 800 ℃ under the protection of gas, hot-dip plating an Al-Mn compound layer with the thickness of 8 mu m on the inner wall of the medium carbon steel crucible A, and then pouring out the magnesium melt;

s3: smelting, namely respectively melting pure magnesium in a medium carbon steel crucible A and a medium carbon steel crucible B at 700 ℃, and naturally cooling the melt in the crucibles after heat preservation for 60 min;

s4: and (3) measuring Fe, namely sampling at the edge and the center of the pure magnesium ingot respectively, and measuring the Fe content in the sample by using an atomic emission spectrometer.

Preferably, the shielding gas in step S2 is CO2+ SF 6.

Compared with the prior art, the invention has the beneficial effects that:

the content of iron is greatly reduced after the Al-Mn compound layer is hot-dipped in the invention, which can effectively prevent the impurity element Fe in the iron crucible from diffusing into the magnesium melt and improve the purity of the magnesium alloy.

Drawings

FIG. 1 is a table showing the measurement results of the iron removal process for surface treatment of a medium carbon steel crucible for smelting kinds of magnesium alloys according to the present invention;

FIG. 2 is a gold phase diagram of the inner surface of the medium carbon steel after hot dipping in the iron removing process for the surface treatment of the medium carbon steel crucible for smelting magnesium alloys.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments, not all embodiments, of the present invention .

Referring to fig. 1, the surface treatment iron removal process for the medium carbon steel crucible for smelting magnesium alloys comprises the following steps:

s1: cleaning the surface, namely taking two medium carbon steel crucibles with the same quality, marking as a medium carbon steel crucible A and a medium carbon steel crucible B, respectively polishing away oxide skins on the inner surfaces of the medium carbon steel crucible A and the medium carbon steel crucible B by 200-mesh abrasive paper, and then cleaning the surface by using alcohol;

s2: hot-dip, putting the medium carbon steel crucible A into a resistance furnace, then pouring the magnesium alloy of Mg with 3 wt.% to 4 wt.% Mn which is melted in advance, preserving the heat for 20min at 800 ℃ under the protection of gas, hot-dip plating an Al-Mn compound layer with the thickness of 8 mu m on the inner wall of the medium carbon steel crucible A, and then pouring out the magnesium melt;

s3: smelting, namely respectively melting pure magnesium in a medium carbon steel crucible A and a medium carbon steel crucible B at 700 ℃, and naturally cooling the melt in the crucibles after heat preservation for 60 min;

s4: and (3) measuring Fe, namely sampling at the edge and the center of the pure magnesium ingot respectively, and measuring the Fe content in the sample by using an atomic emission spectrometer.

Wherein, the shielding gas in step S2 is CO2+ SF 6.

From the measurement results of FIG. 1, in the present invention, the Fe content/ppm at the edge of the ingot in the medium carbon steel crucible B without the hot-dip Al-Mn compound layer was 329, and the Fe content/ppm at the center of the ingot was 159; the Fe content/ppm at the edge of the ingot in the medium carbon steel crucible B hot-dip coated with the Al-Mn compound layer was 40, and the Fe content/ppm at the center of the ingot was 38. Obviously, the content of iron is greatly reduced after the Al-Mn compound layer is hot-dipped, the impurity element Fe in the iron crucible can be effectively prevented from diffusing into the magnesium melt, and the purity of the magnesium alloy is improved.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.