阅读说明：本技术 一种用于模具的材料粉末及模具材料制备方法 (Material powder for die and preparation method of die material ) 是由 孙海霞 郭志猛 王海英 秦乾 杨芳 陈存广 裴广林 于 2019-12-16 设计创作，主要内容包括：本发明公开了一种用于模具的材料粉末,所述材料粉末采用水气联合雾化工艺制备,粉末成分质量百分比如下：C为0.2%~0.6%,Cr为5%~6%,V为6%~12%,Mo为1%~2%,剩余量为Fe。本发明还公开了一种模具材料制备方法,使用上述粉末；采用分解氨气氛进行粉末预处理；将预处理后粉末用压制成型或冷等静压成型,得成型后坯料；将成型后坯料进行预烧结处理；预烧结后用无包套热等静压致密化或用小变形量锻造致密化。本模具材料晶粒细小、碳化物均匀,可提升模具的耐磨性、耐高温性,致密度高,从而能增强模具的疲劳性能；另外本模具材料制备方法可减少锻造次数,缩短工艺流程,采用无包套热等静压时可降低工艺成本。(The invention discloses material powder for a die, which is prepared by adopting a water-gas combined atomization process, and comprises the following components in percentage by mass: 0.2-0.6% of C, 5-6% of Cr, 6-12% of V, 1-2% of Mo and the balance of Fe. The invention also discloses a preparation method of the die material, which uses the powder; performing powder pretreatment in an ammonia decomposition atmosphere; pressing or cold isostatic pressing the pretreated powder to obtain a formed blank; pre-sintering the formed blank; after pre-sintering, densification is carried out by hot isostatic pressing without a sheath or by forging with a small deformation. The die material has fine grains and uniform carbide, can improve the wear resistance and high temperature resistance of the die, and has high density, thereby enhancing the fatigue performance of the die; in addition, the preparation method of the die material can reduce the forging times, shorten the process flow and reduce the process cost when the non-sheath hot isostatic pressing is adopted.)

1. The material powder for the die is prepared by adopting a water-gas combined atomization process, and is characterized by comprising the following components in percentage by mass: 0.2-0.6% of C, 5-6% of Cr, 6-12% of V, 1-2% of Mo and the balance of Fe.

2. The material powder for the die as claimed in claim 1, wherein the powder components are as follows by mass percent: 0.3% of C, 5.1% of Cr, 6.5% of V, 1% of Mo and the balance of Fe.

3. The material powder for the die as claimed in claim 1, wherein the powder components are as follows by mass percent: 0.4% of C, 5.5% of Cr, 9% of V, 1.5% of Mo and the balance of Fe.

4. The material powder for the die as claimed in claim 1, wherein the powder components are as follows by mass percent: 0.5% of C, 5.8% of Cr, 12% of V, 2% of Mo and the balance of Fe.

5. A method for producing a mold material, characterized by using the material powder according to any one of claims 1 to 4, comprising the steps of:

a) preparing material powder by adopting a water-gas combined atomization process, wherein the material powder comprises the following components in percentage by mass: 0.2-0.6% of C, 5-6% of Cr, 6-12% of V, 1-2% of Mo and the balance of Fe;

b) pretreating the powder by adopting a decomposed ammonia atmosphere, wherein the pretreatment temperature is 500-950 ℃, and the pretreatment time is 2-5 h;

c) performing compression molding or cold isostatic pressing on the pretreated powder to obtain a molded blank, wherein the compression pressure is more than or equal to 600MPa, and the cold isostatic pressing pressure is more than or equal to 200 MPa;

d) pre-sintering the formed blank, wherein the pre-sintering treatment comprises two stages, the first stage adopts nitrogen atmosphere sintering, the second stage adopts vacuum sintering, and the vacuum degree is less than or equal to 10^-1Pa; in the first stage, sintering is carried out for 1-2 h from room temperature to 1000-1100 ℃ at a temperature rise rate of 5-10 ℃/min; the second stage sintering takes the first stage sintering temperature as a starting point, the temperature is raised to 1000-1260 ℃ at the rate of 3-5 ℃/min, and the temperature is kept for 1-2 h;

e) after the pre-sintering treatment, performing non-sheath hot isostatic pressing densification or performing small deformation amount forging densification to obtain a final die material; the hot isostatic pressing temperature range of the non-sheath is 900-1100 ℃, the pressure is more than or equal to 100MPa, and the heat preservation and pressure maintaining are carried out for 2 hours; the forging temperature range is 1000-1200 ℃.

6. The method for preparing a mold material according to claim 5, wherein the temperature of the pretreatment in step b) is 650 ℃ or 800 ℃ or 950 ℃.

7. The method for preparing a mold material according to claim 5, wherein the pressing pressure in step c) is 650MPa or 700MPa, and the cold isostatic pressure is 200 MPa.

8. The method for preparing a mold material according to claim 5, wherein the hot isostatic pressing temperature of the hot isostatic pressing without capsule in step e) is 1050 ℃ or 1100 ℃ and the pressure is 100MPa or 150 MPa.

Technical Field

The invention relates to the technical field of dies, in particular to material powder for a die and a preparation method of a die material.

Background

The existing die material is mainly prepared by a casting-forging process, and the wear resistance and the high temperature resistance of the die material are reduced due to the fact that high-alloy die materials have large grains, large carbides and the like in the metallurgical solidification process, so that the fatigue property is reduced, and the die is easy to break and lose efficacy.

Disclosure of Invention

In view of the above, the present invention is to provide a material powder for a mold and a method for preparing a mold material, wherein the mold material has fine crystal grains, uniform carbides and high density, so that fatigue performance can be enhanced, and the service life of the mold can be prolonged; in addition, the preparation method of the die material can reduce the forging times, shorten the process flow and reduce the process cost when the non-sheath hot isostatic pressing is adopted.

In order to achieve the purpose, the invention provides material powder for a die, which is prepared by adopting a water-gas combined atomization process, and comprises the following components in percentage by mass: 0.2-0.6% of C, 5-6% of Cr, 6-12% of V, 1-2% of Mo and the balance of Fe.

Preferably, the powder components are as follows by mass percent: 0.3% of C, 5.1% of Cr, 6.5% of V, 1% of Mo and the balance of Fe.

Preferably, the powder components are as follows by mass percent: 0.4% of C, 5.5% of Cr, 9% of V, 1.5% of Mo and the balance of Fe.

Preferably, the powder components are as follows by mass percent: 0.5% of C, 5.8% of Cr, 12% of V, 2% of Mo and the balance of Fe.

The invention also provides a preparation method of the die material, which uses the material powder and comprises the following steps:

a) preparing material powder by adopting a water-gas combined atomization process, wherein the material powder comprises the following components in percentage by mass: 0.2-0.6% of C, 5-6% of Cr, 6-12% of V, 1-2% of Mo and the balance of Fe;

b) pretreating the powder by adopting a decomposed ammonia atmosphere, wherein the pretreatment temperature is 500-950 ℃, and the pretreatment time is 2-5 h;

c) performing compression molding or cold isostatic pressing on the pretreated powder to obtain a molded blank, wherein the compression pressure is more than or equal to 600MPa, and the cold isostatic pressing pressure is more than or equal to 200 MPa;

d) pre-sintering the formed blank, wherein the pre-sintering treatment comprises two stages, the first stage adopts nitrogen atmosphere sintering, the second stage adopts vacuum sintering, and the vacuum degree is less than or equal to 10^-1Pa; in the first stage, sintering is carried out for 1-2 h from room temperature to 1000-1100 ℃ at a temperature rise rate of 5-10 ℃/min; the second stage sintering takes the first stage sintering temperature as a starting point, the temperature is raised to 1000-1260 ℃ at the rate of 3-5 ℃/min, and the temperature is kept for 1-2 h;

e) after the pre-sintering treatment, performing non-sheath hot isostatic pressing densification or performing small deformation amount forging densification to obtain a final die material; the hot isostatic pressing temperature range of the non-sheath is 900-1100 ℃, the pressure is more than or equal to 100MPa, and the heat preservation and pressure maintaining are carried out for 2 hours; the forging temperature range is 1000-1200 ℃.

Preferably, the temperature of the pretreatment in step b) is 650 ℃ or 800 ℃ or 950 ℃.

Preferably, the pressing pressure in step c) is 650MPa or 700MPa, and the cold isostatic pressure is 200 MPa.

Preferably, the hot isostatic pressing temperature of the non-sheath in the step e) is 1050 ℃ or 1100 ℃, and the pressure is 100MPa or 150 MPa.

The invention has the following beneficial effects: the die material has fine grains and uniform carbide, can improve the wear resistance and high temperature resistance of the die, and has high density, thereby enhancing the fatigue performance and prolonging the service cycle of the die; in addition, the preparation method of the die material can reduce the forging times, shorten the process flow and reduce the process cost when the non-sheath hot isostatic pressing is adopted.

Drawings

FIG. 1 shows the distribution of carbides in the mold material obtained in example 3 of the present invention.

Detailed Description

So that the manner in which the features and aspects of the invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings.

The invention relates to material powder for a die, which is prepared by adopting a water-gas combined atomization process, and comprises the following components in percentage by mass: 0.2-0.6% of C, 5-6% of Cr, 6-12% of V, 1-2% of Mo and the balance of Fe.

Preferably, the powder components are as follows by mass percent: 0.3% of C, 5.1% of Cr, 6.5% of V, 1% of Mo and the balance of Fe.

Preferably, the powder components are as follows by mass percent: 0.4% of C, 5.5% of Cr, 9% of V, 1.5% of Mo and the balance of Fe.

Preferably, the powder components are as follows by mass percent: 0.5% of C, 5.8% of Cr, 12% of V, 2% of Mo and the balance of Fe.

The invention also provides a preparation method of the die material, which uses the material powder and comprises the following steps:

a) preparing material powder by adopting a water-gas combined atomization process, wherein the material powder comprises the following components in percentage by mass: 0.2-0.6% of C, 5-6% of Cr, 6-12% of V, 1-2% of Mo and the balance of Fe;

b) pretreating the powder by adopting a decomposed ammonia atmosphere, wherein the pretreatment temperature is 500-950 ℃, and the pretreatment time is 2-5 h;

here, step b) may remove oxygen from the powder surface while forming a trace amount of vanadium nitride;

c) performing compression molding or cold isostatic pressing on the pretreated powder to obtain a molded blank, wherein the compression pressure is more than or equal to 600MPa, and the cold isostatic pressing pressure is more than or equal to 200 MPa;

d) pre-sintering the formed blank, wherein the pre-sintering treatment comprises two stages, the first stage adopts nitrogen atmosphere sintering, the second stage adopts vacuum sintering, and the vacuum degree is less than or equal to 10^-1Pa; in the first stage, sintering is carried out for 1-2 h from room temperature to 1000-1100 ℃ at a temperature rise rate of 5-10 ℃/min; the second stage sintering takes the first stage sintering temperature as a starting point, the temperature is raised to 1000-1260 ℃ at the rate of 3-5 ℃/min, and the temperature is kept for 1-2 h;

e) after the pre-sintering treatment, performing non-sheath hot isostatic pressing densification or performing small deformation amount forging densification to obtain a final die material; the hot isostatic pressing temperature range of the non-sheath is 900-1100 ℃, the pressure is more than or equal to 100MPa, and the heat preservation and pressure maintaining are carried out for 2 hours; the forging temperature range is 1000-1200 ℃.

Preferably, the temperature of the pretreatment in step b) is 650 ℃ or 800 ℃ or 950 ℃.

Preferably, the pressing pressure in step c) is 650MPa or 700MPa, and the cold isostatic pressure is 200 MPa.

Preferably, the hot isostatic pressing temperature of the non-sheath in the step e) is 1050 ℃ or 1100 ℃, and the pressure is 100MPa or 150 MPa.