阅读说明：本技术 一种硅锶合金变质剂及其制备方法 (Silicon-strontium alloy modifier and preparation method thereof ) 是由 包晓刚 魏爽 史鑫 李有成 卢建华 于 2020-05-15 设计创作，主要内容包括：本发明涉及硅锶合金变质剂及其制备方法,该硅锶合金变质剂的制备方法,包括以下步骤：(1)将单晶硅切削料或多晶硅切削料进行烘干,直至水分含量为1％以下；(2)将80-100重量份的烘干后的单晶硅切削料或多晶硅切削料与20-30重量份的废钢混合,于1300-1450℃条件下进行电加热熔炼,获得合金液；(3)将获得的合金液加入至1-4重量份的金属锶中,进行锶合金化反应,然后进行浇筑成型,获得硅锶合金变质剂。本发明提供的硅锶合金变质剂及其制备方法可降低工艺难度和成本,且控制铝钙元素含量在较低水平。(The invention relates to a silicon-strontium alloy modifier and a preparation method thereof, wherein the preparation method of the silicon-strontium alloy modifier comprises the following steps: (1) drying the monocrystalline silicon cutting material or the polycrystalline silicon cutting material until the moisture content is below 1%; (2) mixing 80-100 parts by weight of dried monocrystalline silicon cutting material or polycrystalline silicon cutting material with 20-30 parts by weight of scrap steel, and carrying out electric heating smelting at 1300-; (3) and adding the obtained alloy liquid into 1-4 parts by weight of metal strontium, carrying out strontium alloying reaction, and then pouring and forming to obtain the silicon-strontium alloy modifier. The silicon-strontium alloy alterant and the preparation method thereof provided by the invention can reduce the process difficulty and cost and control the content of the aluminum-calcium element at a lower level.)

1. The preparation method of the silicon-strontium alloy alterant is characterized by comprising the following steps of:

(1) drying the monocrystalline silicon cutting material or the polycrystalline silicon cutting material until the moisture content is below 1%;

(2) mixing 80-100 parts by weight of dried monocrystalline silicon cutting material or polycrystalline silicon cutting material with 20-30 parts by weight of scrap steel, and carrying out electric heating smelting at 1300-;

(3) and adding the obtained alloy liquid into 1-4 parts by weight of metal strontium, carrying out strontium alloying reaction, and then pouring and forming to obtain the silicon-strontium alloy modifier.

2. The method for preparing the silicon-strontium alloy alterant according to claim 1, wherein the step (1) is specifically as follows: taking water-containing silicon leftovers generated in the slicing process of solar-grade monocrystalline silicon or polycrystalline silicon, carrying out extrusion granulation molding to obtain granules, then drying the granules at 80-150 ℃ until the water content is below 1%, and controlling the proportion of the granules with the grain diameter of 3-12mm in the granules to be above 90% of the total content.

3. The method for preparing the silicon-strontium alloy alterant according to claim 1, wherein the alloy liquid obtained in the step (2) is subjected to slagging-off treatment, and then the alloy liquid after slagging-off treatment is added into the metal strontium.

4. The method for preparing the silicon-strontium alloy alterant according to claim 3, wherein the slagging-off treatment is specifically as follows: adding 1-3 parts of slag conglomeration agent into the obtained alloy liquid, and continuously carrying out heat preservation smelting for 1-3min at the temperature of 1300-1450 ℃ after slag is removed.

5. The method of claim 1, wherein in step (1), the alloy liquid is added to the strontium metal covered with the covering agent.

6. The method for preparing the silicon-strontium alloy alterant according to claim 5, wherein the covering agent is one or more of monocrystalline silicon powder, polycrystalline silicon powder, steel scrap, reduced iron powder and silicon-strontium alloy powder.

7. The method of claim 1, wherein the scrap is of a steel grade having an aluminum content of 0.3% or less.

8. The method of claim 1, wherein the purity of the strontium metal is 99.9% or higher.

9. The silicon-strontium alloy alterant is characterized by comprising the following raw materials in percentage by mass: 70-78% of silicon, 0.8-2.8% of metal strontium, less than 0.08% of aluminum, less than 0.05% of calcium and the balance of iron.

10. The silicon-strontium alloy alterant is characterized by being prepared from the following raw materials in parts by weight: 80-100 parts of monocrystalline silicon cutting materials or polycrystalline silicon cutting materials, 20-30 parts of scrap steel and 1-4 parts of strontium.

Technical Field

The invention relates to an alloy metal material technology, in particular to a silicon-strontium alloy alterant and a preparation method thereof.

Background

The silicon-strontium alloy alterant comprises the main element components of Si and Sr, and the balance of Fe. The Sr is the most effective element for promoting inoculation in the ferrosilicon inoculant, and has the special function of reducing eutectic clusters when the supercooling degree is higher, so that the defects of shrinkage cavity and shrinkage porosity of castings can be reduced. The strontium-silicon alloy is used as an inoculant, and compared with ferrosilicon, the white cast reduction capability of the strontium-silicon alloy is higher than that of ferrosilicon by more than 50 percent, and the eutectic cell number is not increased obviously. Therefore, the alloy is often used for thin-wall or quenching high-sulfur and low-sulfur gray iron parts and nodular iron parts needing increasing the nodular number, and is particularly suitable for corrosion-resistant cast iron and water-resistant die castings. Meanwhile, the content of Al and Ca in the silicon-strontium alloy is controlled to be low, the traveling slag of the casting is less, no pinhole defect exists, and the method plays an important role in the inoculation of precise and special castings.

The traditional silicon-strontium preparation process mainly comprises a submerged arc furnace smelting process and an induction furnace smelting process. The ore smelting furnace process uses silica, strontium ore and the like as raw materials to perform reduction smelting on the silicon-strontium alloy in the ore smelting furnace, and the alloy components are difficult to control due to the large fluctuation of the complicated components of the furnace conditions so as to prepare the low-aluminum low-calcium silicon-strontium alloy; in addition, normal ferrosilicon can be added into the submerged arc furnace, chlorine gas/oxygen blowing is carried out after melting, dealumination and decalcification are carried out, and the molten iron outside the furnace is buried with strontium for casting and smelting, so that the blowing process of the method has certain negative effect on the environment; the smelting process of the induction furnace is mainly characterized in that low-aluminum low-calcium high-purity ferrosilicon and metal strontium are directly added into the induction furnace to prepare the silicon-strontium alloy by a remelting method. The method is the mainstream technology of the existing strontium-silicon production, and the process is adopted to obtain the low-aluminum low-calcium strontium-silicon alloy, so that the problems of high cost, high process difficulty and the like exist.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the preparation method of the silicon-strontium alloy alterant can reduce the cost and the process difficulty and obtain the low-aluminum and low-calcium silicon-strontium alloy. And provides a silicon-strontium alloy modifier based on the preparation method.

In order to solve the technical problems, the invention adopts the technical scheme that:

the invention provides a preparation method of a silicon-strontium alloy alterant, which comprises the following steps:

(1) drying the monocrystalline silicon cutting material or the polycrystalline silicon cutting material until the moisture content is below 1%;

(2) mixing 80-100 parts by weight of dried monocrystalline silicon cutting material or polycrystalline silicon cutting material with 20-30 parts by weight of scrap steel, and carrying out electric heating smelting at 1300-;

(3) and adding the obtained alloy liquid into 1-4 parts by weight of metal strontium, carrying out strontium alloying reaction, and then pouring and forming to obtain the silicon-strontium alloy modifier.

The invention also provides a silicon-strontium alloy alterant, which consists of the following raw materials in percentage by mass: 70-78% of silicon, 0.8-2.8% of metal strontium, less than 0.08% of aluminum, less than 0.05% of calcium and the balance of iron.

The invention also provides a silicon-strontium alloy alterant which is prepared from the following raw materials in parts by weight: 80-100 parts of monocrystalline silicon cutting materials or polycrystalline silicon cutting materials, 20-30 parts of scrap steel and 1-4 parts of strontium.

The invention has the beneficial effects that:

by the design of the preparation process and the electric heating smelting technology, the silicon-strontium alloy modifier can be prepared by electrically heating the preparation raw materials (for example, the existing electric heating furnace is used for electric heating smelting) for one-time smelting, the content of aluminum in the alloy is less than 0.08%, the content of calcium in the alloy is less than 0.05%, the content of aluminum and calcium in the alloy is lower, the alloy can be applied to molten iron out-of-furnace treatment, the treatment temperature requirement is low, the process difficulty is correspondingly reduced, inoculation can be effectively promoted, the eutectic colony number, pinhole defects and the tendency of shrinkage porosity and shrinkage cavity of a casting can be remarkably reduced, and the casting with excellent performance can be produced. Meanwhile, the process adopts leftovers and waste steel produced in the slicing process of the single/polycrystalline silicon as raw materials, the strontium yield reaches over 84 percent, and the production cost is greatly reduced.

Drawings

FIG. 1 is a photograph of a granulated material in a method for preparing a silicon-strontium alloy alterant according to an embodiment of the present invention;

FIG. 2 is a photograph of the product inside the furnace before discharging in the later stage of high-temperature melting using an induction heating furnace in the method for preparing a silicon-strontium alloy alterant according to the embodiment of the invention;

FIG. 3 is an enlarged view of an electron microscope showing the number of eutectic cells obtained by a test in which the silicon-strontium alloy modifier of example 5 of the present invention is applied to a downstream casting;

FIG. 4 is a microscopic magnified view of the silicon-strontium alloy alterant of example 5 of the present invention applied to a downstream casting after experimental cut-away of the casting showing substantial absence of pinhole defects and shrinkage porosity;

FIG. 5 is another microscopic image of the silicon-strontium alloy modifier of example 5 of the present invention applied to the downstream casting after experimental cut-open of the casting showing substantial pinhole defects and no shrinkage porosity.

Detailed Description

In order to explain technical contents, achieved objects, and effects of the present invention in detail, the following description is made with reference to the accompanying drawings in combination with the embodiments.

The most key concept of the invention is as follows: the low-aluminum low-calcium silicon-strontium alloy modifier is prepared from a single/polycrystalline silicon cutting material, scrap steel and a metal strontium raw material by an electrical heating melting process.

The preparation method of the silicon-strontium alloy alterant provided by the invention comprises the following steps:

(1) drying the monocrystalline silicon cutting material or the polycrystalline silicon cutting material until the moisture content is below 1%;

(2) mixing 80-100 parts by weight of dried monocrystalline silicon cutting material or polycrystalline silicon cutting material with 20-30 parts by weight of scrap steel, and carrying out electric heating smelting at 1300-;

(3) and adding the obtained alloy liquid into 1-4 parts by weight of metal strontium, carrying out strontium alloying reaction, and then pouring and forming to obtain the silicon-strontium alloy modifier. From the above description, it can be seen that the beneficial effects of the present invention are:

by the design of the preparation process and the electric heating smelting technology, the silicon-strontium alloy modifier can be prepared by electrically heating the preparation raw materials (for example, the existing electric heating furnace is used for electric heating smelting) for one-time smelting, the content of aluminum in the alloy is less than 0.08%, the content of calcium in the alloy is less than 0.05%, the content of aluminum and calcium in the alloy is lower, the alloy can be applied to molten iron out-of-furnace treatment, the treatment temperature requirement is low, the process difficulty is correspondingly reduced, inoculation can be effectively promoted, the eutectic colony number, pinhole defects and the tendency of shrinkage porosity and shrinkage cavity of a casting can be remarkably reduced, and the casting with excellent performance can be produced. Meanwhile, the process adopts powder leftovers and waste steel produced in the mono/polycrystalline silicon slicing process as raw materials, the strontium yield reaches over 84 percent, and the production cost is greatly reduced.

Further, the step (1) is specifically as follows: the method comprises the steps of taking leftovers of water-containing silicon powder generated in the slicing process of solar-grade monocrystalline silicon or polycrystalline silicon, carrying out extrusion granulation molding to obtain granules, then drying the granules at 80-150 ℃ until the water content is below 1%, and controlling the proportion of granules with the particle size of 3-12mm in the granules to be above 90% of the total content.

Further, the alloy liquid obtained in the step (2) is subjected to slag skimming treatment, and then the alloy liquid subjected to slag skimming treatment is added into the metal strontium.

Further, the slag skimming treatment specifically comprises the following steps: adding 1-3 parts of slag conglomeration agent into the obtained alloy liquid, and continuously carrying out heat preservation smelting for 1-3min at the temperature of 1300-1450 ℃ after slag is removed.

Further, in the step (1), the alloy liquid is added into the metal strontium covered with the covering agent.

The invention provides a silicon-strontium alloy alterant, which comprises the following raw materials in percentage by mass: 70-78% of silicon, 0.8-2.8% of metal strontium, less than 0.08% of aluminum, less than 0.05% of calcium and the balance of iron.

The silicon-strontium alloy alterant provided by the invention is prepared from the following raw materials in parts by weight: 80-100 parts of monocrystalline silicon cutting materials or polycrystalline silicon cutting materials, 20-30 parts of scrap steel and 1-4 parts of strontium.

Among the raw materials adopted by the invention, the monocrystalline silicon cutting material or the polycrystalline silicon cutting material can be leftovers generated in the single/polycrystalline silicon slicing process, the leftovers can be powder materials, preferably the leftovers of high-purity water-containing silicon powder generated in the solar grade single/polycrystalline silicon plate slicing process, and preferably, the purity of the metal strontium is more than 99.9%. The scrap steel is steel with the aluminum content less than or equal to 0.3 percent. The selected covering agent is one or more of monocrystalline silicon powder, polycrystalline silicon powder, waste steel material, reduced iron powder and silicon-strontium alloy powder.

The examples of the invention are as follows: