阅读说明：本技术 一种TiC颗粒增强高铬铸铁合金材料的制备方法 (Preparation method of TiC particle reinforced high-chromium cast iron alloy material ) 是由 肖平安 顾景洪 吕蓉 肖利洋 石管华 肖雨桐 古思敏 于 2020-05-27 设计创作，主要内容包括：本发明公开了一种TiC颗粒增强高铬铸铁合金材料的制备方法,包括：(1)合金配比设计：TiC增强颗粒粉末的添加量为5wt％～35wt％,粒度为200～3000nm；高铬铸铁预合金粉末的添加量为65wt％～95wt％；(2)球磨混料：采用干混或者湿混的方式实现TiC增强颗粒粉末的均匀分布；(3)压坯烧结致密化：向混合好的原料粉末中加入适量成型剂,先模压成坯,然后实现合金的烧结致密化；(4)淬火处理：淬火温度为880℃～1100℃,保温时间为1h～6h；(5)回火处理：回火温度为150～500℃,保温时间为1h～6h。本发明产品合金的硬度为HRC75～HRC65,抗弯强度为2500～1000MPa,冲击韧性在20～4J/cm<Sup>2</Sup>；与WC-Co硬质合金相比,该类新型合金不仅硬度和强韧性优异,而且由于使用廉价的TiC颗粒为强化相和高铬铸铁为基体,使得合金的原料成本和比重显著降低。(The invention discloses a preparation method of a TiC particle reinforced high-chromium cast iron alloy material, which comprises the following steps: (1) alloy proportioning design: the addition amount of the TiC reinforced particle powder is 5-35 wt%, and the particle size is 200-3000 nm; the addition amount of the high-chromium cast iron prealloying powder is 65-95 wt%; (2) ball milling and mixing: the TiC reinforced particle powder is uniformly distributed in a dry mixing or wet mixing mode; (3) and (3) compact sintering densification: adding a proper amount of forming agent into the mixed raw material powder, and firstlyPressing into a blank, and then realizing sintering densification of the alloy; (4) quenching treatment: the quenching temperature is 880-1100 ℃, and the heat preservation time is 1-6 h; (5) tempering treatment: the tempering temperature is 150-500 ℃, and the heat preservation time is 1-6 h. The alloy of the invention has the hardness of HRC 75-HRC 65, the bending strength of 2500-1000 MPa and the impact toughness of 20-4J/cm 2 (ii) a Compared with WC-Co hard alloy, the novel alloy has excellent hardness and obdurability, and because the cheap TiC particles are used as a strengthening phase and the high-chromium cast iron is used as a matrix, the raw material cost and the specific gravity of the alloy are obviously reduced.)

1. A preparation method of a TiC particle reinforced high-chromium cast iron alloy material is characterized by comprising the following steps:

(1) alloy proportioning design: the addition amount of the TiC reinforced particle powder is 5-35 wt%, and the particle size is 200-3000 nm; the addition amount of the high-chromium cast iron prealloying powder is 65-95 wt%;

(2) ball milling and mixing: carrying out alloy preparation on high-chromium cast iron prealloying powder and TiC reinforced particle powder, and realizing uniform distribution of the TiC reinforced particle powder in a dry mixing or wet mixing mode;

(3) and (3) compact sintering densification: adding a proper amount of forming agent into the mixed raw material powder, firstly, carrying out die pressing to form a blank, and then, realizing the sintering densification of the alloy;

(4) quenching treatment: heating the alloy product prepared by sintering, and then carrying out quenching heat treatment, wherein the quenching temperature is 880-1100 ℃, the heat preservation time is 1-6 h, and the cooling mode is air cooling or room temperature water quenching;

(5) tempering treatment: and tempering the quenched alloy product, wherein the tempering temperature is 150-500 ℃, the heat preservation time is 1-6 h, and the tempering times can be selected to be 1-5 times.

2. The TiC particle-reinforced high-chromium cast iron alloy material according to claim 1, wherein in step (1), said high-chromium cast iron pre-alloyed powder is a commercially common composition comprising: 11-30% of Cr, 2.0-3.5% of C, 0.5-2.0% of Si, 0.5-2.0% of Mn, 0.8-2.0% of Ni, 1.0-3.5% of Mo, 1.0-3% of W, 1-3% of V, 0.005-0.10% of B, less than 0.10% of P and S, and the balance of Fe, wherein the sum of the mass of the components is 100%.

3. The preparation method of the TiC particle-reinforced high-chromium cast iron alloy material according to claim 1, wherein in the step (1), the addition amount of TiC reinforced particle powder is 8-30 wt%, and the particle size is 350-2500 nm; the addition amount of the high-chromium cast iron prealloying powder is 70-92 wt%.

4. The TiC particle-reinforced high-chromium cast iron alloy material preparation method according to claim 1, wherein in the step (3), the green compact pressing force is controlled at 200-280 MPa.

5. The preparation method of the TiC particle-reinforced high-chromium cast iron alloy material according to claim 3 or 4, characterized in that in the step (1), the addition amount of TiC reinforced particle powder is 8 wt% -25 wt%, and the particle size is 450-1800 nm; the addition amount of the high-chromium cast iron prealloying powder is 75-92 wt%; and (3) controlling the pressing force of the pressed blank to be 220-280 MPa.

6. The preparation method of the TiC particle-reinforced high-chromium cast iron alloy material according to claim 5, wherein in the step (1), the addition amount of TiC reinforced particle powder is 8-20 wt%, and the particle size is 450-1200 nm; the addition amount of the high-chromium cast iron prealloying powder is 80-92 wt%; and (3) controlling the pressing force of the pressed blank to be 250-280 MPa.

7. The method of claim 1, wherein in step (3), the alloy is densified by sintering under vacuum, by hot pressing, or by hot isostatic pressing.

8. The method of claim 1, wherein in step (3), the relative density of the sintered article is more than 97% after the sintering densification.

9. The method of claim 1, wherein in step (4), the quenching temperature is 50 ℃ to 100 ℃ above the austenitizing temperature of the alloy.

10. The TiC particle-reinforced high-chromium cast iron alloy material prepared by the preparation method of the TiC particle-reinforced high-chromium cast iron alloy material according to any one of claims 1 to 9.

Technical Field

The invention belongs to the field of wear-resistant alloy materials, relates to a preparation method of a TiC particle reinforced high-chromium cast iron alloy material, and particularly relates to a preparation method of a TiC particle reinforced sintered high-chromium cast iron alloy material containing 11-30% of Cr.

Background

The sintered high-chromium cast iron containing 11-30% of Cr is one of alloy series with excellent performance in the third generation of metal wear-resistant materials, and compared with hard alloy (WC-Co hard alloy), the hardness is slightly inferior, but the indexes such as impact toughness, alloy specific gravity and the like are far superior to most hard alloys, and the cost is obviously lower than that of the hard alloy. TiC is a hard carbide with outstanding microhardness, low friction coefficient and excellent antifriction and antiwear performances.

The cast high-chromium cast iron is very easy to generate strong stress concentration due to the existence of petal-shaped carbide, so that the alloy is easy to crack under the action of quenching and impact force, and the carbide in the sintered high-chromium cast iron is in a shape of a blunt, fine and short rod and is uniformly distributed, so that the sintered high-chromium cast iron has good bearing capacity in the action of quenching and impact force. In addition, TiC particles are generally less wettable with iron-based alloys, making effective sintering densification difficult.

Disclosure of Invention

Aiming at the technical problems that petaloid carbide exists in the cast high-chromium cast iron in the prior art, the alloy is easy to crack under the action of quenching, quenching and impact force, TiC particles are generally poor in wettability with iron-based alloy, and effective sintering densification is difficult to realize, the invention aims to provide a preparation method of a TiC particle reinforced high-chromium cast iron alloy material with simple preparation process and short production flow, the TiC particle reinforced high-chromium cast iron alloy with the wear resistance equivalent to that of WC-Co hard alloy is prepared, and the production cost is obviously reduced.

In order to achieve the purpose, the invention provides the following technical scheme: a preparation method of a TiC particle reinforced high-chromium cast iron alloy material comprises the following steps:

(1) alloy proportioning design: the addition amount of the TiC reinforced particle powder is 5-35 wt%, and the particle size is 200-3000 nm; the addition amount of the high-chromium cast iron prealloying powder is 65-95 wt%;

(2) ball milling and mixing: carrying out alloy preparation on high-chromium cast iron prealloying powder and TiC reinforced particle powder, and realizing uniform distribution of the TiC reinforced particle powder in a dry mixing or wet mixing mode to prevent the TiC reinforced particle powder from agglomerating or deviating;

(3) and (3) compact sintering densification: adding a proper amount of forming agent into the mixed raw material powder, firstly, carrying out die pressing to form a blank, and then, realizing the sintering densification of the alloy;

(4) quenching treatment: heating the alloy product prepared by sintering, and then carrying out quenching heat treatment, wherein the quenching temperature is 880-1100 ℃, the heat preservation time is 1-6 h, and the cooling mode is air cooling or room temperature water quenching;

(5) tempering treatment: tempering the quenched alloy product, wherein the tempering temperature is 150-500 ℃, the heat preservation time is 1-6 h, and the tempering times can be selected to be 1-5 times; the quenched alloy article is further tempered to achieve the hardness required by the design.

Preferably, in step (1), the high-chromium cast iron prealloyed powder is a commercially common component, and comprises the following components: 11-30% of Cr, 2.0-3.5% of C, 0.5-2.0% of Si, 0.5-2.0% of Mn, 0.8-2.0% of Ni, 1.0-3.5% of Mo, 1.0-3% of W, 1-3% of V, 0.005-0.10% of B, less than 0.10% of P and S, and the balance of Fe, wherein the sum of the mass of the components is 100%.

In the preferable scheme, in the step (1), the addition amount of the TiC reinforced particle powder is 8-30 wt%, and the particle size is 350-2500 nm; the addition amount of the high-chromium cast iron prealloying powder is 70-92 wt%.

Preferably, in the step (3), the control of the pressing force of the pressed compact is 200-280 MPa.

In a more preferable scheme, in the step (1), the addition amount of the TiC reinforced particle powder is 8-25 wt%, and the particle size is 450-1800 nm; the addition amount of the high-chromium cast iron prealloying powder is 75-92 wt%; and (3) controlling the pressing force of the pressed blank to be 220-280 MPa.

In a more preferable scheme, in the step (1), the addition amount of the TiC reinforced particle powder is 8-20 wt%, and the particle size is 450-1200 nm; the addition amount of the high-chromium cast iron prealloying powder is 80-92 wt%; and (3) controlling the pressing force of the pressed blank to be 250-280 MPa.

Preferably, in the step (3), the sintering densification of the alloy is realized by any one of vacuum sintering, hot-pressing sintering or hot isostatic pressing.

Preferably, in the step (3), after sintering densification, the relative density of the sintered product is required to reach more than 97%.

Preferably, in the step (4), the quenching temperature is 50-100 ℃ above the austenitizing temperature of the alloy, and the heat preservation time and the temperature rise rate are determined according to the size and the shape of an actual sample.

In the preferable scheme, in the step (4), the temperature rise rate is 4-8 ℃/min in the quenching treatment process.

Wherein, the obtained alloy product is subjected to room temperature Rockwell hardness test and room temperature impact toughness test, and the test method adopts the national standard GB/T6884-1986.

Experiments show that after the TiC particle reinforced sintered high-chromium cast iron is subjected to quenching and hard heat treatment, the alloy consists of TiC reinforced particles which are uniformly distributed and a high-chromium cast iron matrix, and the high-chromium cast iron matrix consists of short rod-shaped chromium carbide, martensite and a small amount of austenite which are uniformly distributed.

The TiC particle reinforced sintered high-chromium cast iron containing 11-30% of Cr and having high hardness and high wear resistance is prepared, TiC reinforced particle powder and cast iron alloy with low melting point and low viscosity have good mutual wettability, and full-compact sintering of the TiC reinforced particle powder and the cast iron alloy can be effectively realized, so that alloy structure can be refined and alloy hardness can be effectively improved. The TiC particle reinforced sintered high chromium cast iron composite material can realize the obvious improvement of alloy hardness and wear resistance through hard carbide particle reinforcement and quenching-tempering heat treatment, and the toughness and the macro hardness of the alloy can be comparable with those of WC-Co hard alloy.

The mechanism of the invention is as follows: the TiC particles can be used as heterogeneous hard points to prevent grains from merging and growing in the sintering and densifying process of the high-chromium cast iron pressed compact, and can be used as a hard phase with high hardness and good antifriction effect while refining the structure, so that the hardness and the wear resistance of the alloy are further improved; then quenching and hardening heat treatment are carried out, the strength and hardness of the alloy can be compared with expensive WC-Co hard alloy with high specific gravity, and the preparation cost and the specific gravity of the alloy are greatly reduced. Therefore, the alloy can replace part of WC-Co hard alloy in the production of products requiring high wear resistance, not only can save W, Co strategic metal resources in China, but also can generate obvious economic benefit.

Compared with the prior art, the invention has the advantages that:

(1) the hardness of the alloy product is HRC 75-HRC 65, and the impact toughness is 10-3J/cm²Compared with WC-Co hard alloy, the novel alloy has excellent hardness and toughness, and because cheap TiC particles are used as a strengthening phase and high-chromium cast iron is used as a matrix, the raw material cost and the specific gravity of the alloy are obviously reduced.

(2) The possible application range of TiC particle reinforced sintered high-chromium cast iron is as follows: the sliding wear/abrasive wear, rolling wear/abrasive wear, scouring wear and impact work are 1J/cm²Parts requiring high hardness and/or wear resistance, such as low impact abrasive wear, wear seals, and the likeManufacturing; the TiC particle reinforced sintered high-chromium cast iron wear-resistant material with ultrahigh hardness and low cost has great significance for the production of wear-resistant products in the fields of mine metallurgy, capital construction traffic and the like, and is suitable for industrial application.

Drawings

FIG. 1 shows the 10% D content obtained in example 1₅₀400nmTiC grain reinforced sintered high chromium cast iron-gold phase diagram.

FIG. 2 shows the 15% D content obtained in example 2₅₀The TiC particles with the size of 400nm strengthen the gold phase diagram of the sintered high-chromium cast iron.

FIG. 3 shows 20% D content obtained in example 3₅₀The TiC particles with the size of 400nm strengthen the gold phase diagram of the sintered high-chromium cast iron.

FIG. 4 shows the 15% D content obtained in example 4₅₀The TiC particles with the size of 700nm strengthen the gold phase diagram of the sintered high-chromium cast iron.

FIG. 5 is a metallographic picture of high-chromium cast iron obtained in comparative example 1.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments, and all other embodiments obtained by those skilled in the art without any creative work based on the embodiments of the present invention belong to the protection scope of the present invention.

The following are some examples of the inventors in their experiments: