阅读说明：本技术 一种新型纳米中碳结构钢及其制备方法 (Novel nano medium carbon structural steel and preparation method thereof ) 是由 王伟 于 2020-05-22 设计创作，主要内容包括：本发明公开了一种新型纳米中碳结构钢及其制备方法。本发明通过在中碳结构钢基体原料粉末中添加一定量的纳米铝粉,纳米铝粉能够在中碳结构钢基体中均匀弥散形成纳米晶核,然后诱导基体钢结构形成平均晶粒尺寸不超过100nm的均匀纳米结构,从而对中碳结构钢的性能产生增强效果。(The invention discloses novel nano medium carbon structural steel and a preparation method thereof. According to the invention, a certain amount of nano aluminum powder is added into the raw material powder of the medium carbon structure steel matrix, the nano aluminum powder can be uniformly dispersed in the medium carbon structure steel matrix to form nano crystal nuclei, and then the matrix steel structure is induced to form a uniform nano structure with the average grain size not exceeding 100nm, so that the performance of the medium carbon structure steel is enhanced.)

1. The novel nano medium carbon structural steel is characterized by being prepared from a base raw material and nano aluminum powder, wherein the average grain size of the nano medium carbon structural steel is less than 100nm, and the nano medium carbon structural steel comprises the following components in percentage by mass: aluminum: 1.5% -2.5%, carbon: 0.42% -0.50%, manganese: 0.5% -0.8%, silicon: 0.17% -0.37%, chromium: less than or equal to 0.25 percent, nickel: less than or equal to 0.3 percent, and the balance of iron and inevitable impurities.

2. The novel nano medium carbon structural steel according to claim 1, wherein the mass percentage of aluminum in the nano medium carbon structural steel is 1.8% -2.3%.

3. The novel nano medium carbon structural steel according to claim 2, wherein the nano medium carbon structural steel comprises the following components in percentage by mass: aluminum: 1.8% -2.3%, carbon: 0.45%, 0.5% -0.8% of manganese, silicon: 0.17% -0.37%, chromium: less than or equal to 0.25 percent, nickel: less than or equal to 0.3 percent, and the balance of iron and inevitable impurities.

4. The novel nano medium carbon structural steel according to claim 3, wherein the average grain size of the nano medium carbon structural steel is 50nm or less.

5. A novel nano medium carbon structural steel according to any one of claims 1 to 4, wherein the average particle size of the nano aluminum powder is 10 to 50 nm.

6. The novel nano medium carbon structural steel according to any one of claims 1 to 4, wherein the impurity is phosphorus, and the mass percentage of the impurity in the nano medium carbon structural steel is less than or equal to 0.035%.

7. The method for preparing the novel nano medium carbon structural steel as claimed in any one of claims 1 to 6, wherein the nano medium carbon structural steel with the average grain size of less than 100nm is obtained by mixing nano aluminum powder and a base raw material in proportion, heating to more than 1500 ℃, and cooling after smelting.

Technical Field

The invention relates to the technical field of nano alloy, in particular to novel nano medium carbon structural steel and a preparation method thereof.

Background

The nano material has wide application prospect in the fields of electronic information, bioengineering, aerospace and the like due to unique physical, chemical and mechanical properties. However, most of the existing nano materials refer to nano powder materials, and the bulk nano materials are limited by factors such as preparation technology, material formula and the like, so that industrial production is difficult to realize. At present, the manufacturing of the massive nano alloy or the complex processes of nano powder high-temperature sintering, large plastic deformation and the like are adopted, and the severe conditions of high temperature, high pressure and the like are needed, so that only massive nano products with larger grain size, rough interface and excessive micropores can be prepared; or an amorphous crystallization method is adopted, a special material formula is adopted, firstly, amorphous solid is obtained, and then the amorphous state is converted into the crystalline state by methods such as melt chilling and the like, so that the blocky nano product is prepared. The preparation method of the blocky nano material depends on the formula of the material on one hand and the complex preparation process on the other hand, and the prepared blocky nano product still has poor quality, thereby limiting the industrial application of the blocky nano alloy.

Based on the current situation of the preparation process of the bulk nano material, it is necessary to develop a bulk nano medium carbon structural steel with simple preparation process, uniform nano crystal grain size and small micropores.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide novel nano medium carbon structural steel and a preparation method thereof.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

the novel nano medium carbon structural steel is prepared from a base raw material and nano aluminum powder, the average grain size of the nano medium carbon structural steel is less than 100nm, and the nano medium carbon structural steel comprises the following components in percentage by mass: aluminum: 1.5% -2.5%, carbon: 0.42% -0.50%, manganese: 0.5% -0.8%, silicon: 0.17% -0.37%, chromium: less than or equal to 0.25 percent, nickel: less than or equal to 0.3 percent, and the balance of iron and inevitable impurities.

In the smelting process, nano aluminum powder is added into the raw material powder of the medium carbon structural steel (45#) matrix, the nano aluminum powder is uniformly dispersed in the medium carbon structural steel matrix to form nano crystal nuclei, then the growth of steel alloy crystal grains is induced, the crystal grains of the steel alloy are prevented from being excessively grown by controlling the content of the nano aluminum, the average crystal grain size of the steel alloy is ensured to be below 100nm, and the mechanical strength and other properties of the steel material are integrally enhanced. The preparation process is simple and is beneficial to realizing the industrial production of the nano medium carbon structural steel.

Further, the mass percent of aluminum in the nano medium carbon structural steel is 1.8-2.3%, and the nano aluminum powder can be uniformly dispersed in a medium carbon structural steel matrix to form nano crystal nuclei by preferably selecting the addition amount of the nano aluminum powder, so that the mechanical strength and hardness of the nano medium carbon structural steel are further improved.

Further, the components of the nano medium carbon structural steel comprise, by mass: aluminum: 1.8% -2.3%, carbon: 0.45%, manganese: 0.5% -0.8%, silicon: 0.17% -0.37%, chromium: less than or equal to 0.25 percent, nickel: less than or equal to 0.3 percent, and the balance of iron and inevitable impurities, which is more favorable for improving the mechanical strength and hardness of the nano medium carbon structural steel.

Furthermore, the average grain size of the nano medium carbon structural steel is less than or equal to 50nm, so that the nano medium carbon structural steel has higher hardness and mechanical strength.

Further, the average particle size of the nano aluminum powder is 10-50 nm. The nano aluminum powder is used as a nucleating agent of medium carbon structural steel to induce the formation of a nano structure, and in order to prevent the excessive increase of crystal grains, the particle size of the nano aluminum powder is preferably below 50nm, while the aluminum powder below 10nm is easy to agglomerate due to too small particle size, and is not beneficial to the formation of a uniform nano structure.

Further, the impurities are phosphorus, and the mass percent of the impurities in the nano medium carbon structural steel is less than or equal to 0.035%.

The invention also provides a preparation method of the novel nano medium carbon structural steel, which comprises the steps of proportioning the nano aluminum powder and the matrix raw material in proportion, uniformly mixing, heating to more than 1500 ℃, smelting, and cooling to obtain the nano medium carbon structural steel with the average grain size of less than 100 nm. The preparation process is simple, and the prepared carbon-in-carbon structural steel has uniform nanocrystalline grain size, small micropores and higher mechanical strength.

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

according to the invention, nano aluminum powder is added into the medium-carbon structural steel raw material powder, and the addition amount of the nano aluminum powder is optimized, so that the nano aluminum powder can be uniformly dispersed in a medium-carbon structural steel matrix to form a nano crystal nucleus, and then the steel structure is induced to form a uniform nano structure with the average grain size not more than 100nm, thereby achieving the purpose of nano reinforcement.

Drawings

Fig. 1 is an SEM image of the nano medium carbon structural steel of example 1.

Detailed Description

To better illustrate the objects, aspects and advantages of the present invention, the present invention will be further described with reference to specific examples. It will be understood by those skilled in the art that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.