WO2015066952A1

WO2015066952A1 - High-performance powder metallurgy stainless steel and preparation method for same

Info

Publication number: WO2015066952A1
Application number: PCT/CN2013/089652
Authority: WO
Inventors: 郑勇
Original assignee: 常熟市迅达粉末冶金有限公司
Priority date: 2013-11-11
Filing date: 2013-12-17
Publication date: 2015-05-14
Also published as: CN103820730A; CN103820730B

Abstract

The present invention discloses a high-performance power metallurgy stainless steel, composed of the following weight percentages: 316L austenitic stainless steel 92.5-97.0%, FeB 0.5-1.5%, FeMo60 1-3%, TiC 1-3%; the manufacturing method is to blend, ball mill, press-mould, degrease, and vacuum sinter the original ingredients to obtain high-performance powder metallurgy stainless steel. By means of said method of adding sintering aids and strengthening phases, the powder metallurgy stainless steel and preparation method in the present invention allows a great improvement in density, having excellent corrosion resistance, oxidation resistance, and better overall mechanical properties, and can be used for manufacturing devices or elements which can withstand certain loads and which have a high demand for corrosion resistance and oxidation resistance, thus having wide applications in the fields of mechanics, chemistry, petroleum, marine and light industry.

Description

一种高性能粉末冶金不锈钢及其制备方法技术领域 High performance powder metallurgy stainless steel and preparation method thereof

本发明涉及金属材料领域，特别是涉及一种高性能粉末冶金不锈钢及其制备方法。背景技术 The present invention relates to the field of metallic materials, and more particularly to a high performance powder metallurgy stainless steel and a method of preparing the same. Background technique

不锈钢是一种耐腐蚀介质腐蚀的钢，能够抗氧化，具有较高的强度、韦刃性、抗冲击性等力学性能和无磁性、淬硬性等特点，因而在汽车、水利、环保和建筑等工业部门及日常生活中得到了广泛应用，为近代工业的发展和科技进步奠定了重要物质技术基础。不锈钢一般釆用熔炼法生产，但由其制造的零件切削加工困难、尺寸精度差、表面粗糙，且形状上受一定限制，易产生元素偏析，有缩孔、砂眼等缺点。在 20世纪 70年代，人们开始釆用雾化法制取不锈钢预合金粉末，进而利用粉末冶金技术制备出高性能的不锈钢。粉末冶金不锈钢具有良好的力学、物理和化学性能，与传统熔炼技术生产的不锈钢相比，因具有烧结温度低、接近净成型、尺寸精度高、材料利用率高、组织结构均勾等优点，使其在生产应用中具有较大优势，已广泛应用于机械、化工、船舶、汽车、仪器仪表等行业。 Stainless steel is a corrosion-resistant medium that is resistant to corrosion. It has high strength, high edge resistance, impact resistance and other mechanical properties, and is non-magnetic and hardenable. Therefore, it is used in automobiles, water conservancy, environmental protection and construction. It has been widely used in the industrial sector and in daily life, laying an important material and technical foundation for the development of modern industry and scientific and technological progress. Stainless steel is generally produced by smelting, but the parts manufactured by it are difficult to cut, have poor dimensional accuracy, have a rough surface, and are limited in shape, and are prone to segregation of elements, such as shrinkage cavities and blisters. In the 1970s, people began to use the atomization method to prepare stainless steel prealloyed powder, and then used powder metallurgy technology to prepare high performance stainless steel. Powder metallurgy stainless steel has good mechanical, physical and chemical properties. Compared with stainless steel produced by traditional smelting technology, it has the advantages of low sintering temperature, close to net shape, high dimensional accuracy, high material utilization rate, and uniform structure. It has great advantages in production and application, and has been widely used in machinery, chemical, shipbuilding, automotive, instrumentation and other industries.

但同时由于粉末冶金不锈钢内部存在孔隙，其力学性能和耐腐蚀性都不及致密不锈钢，从而较大地限制了其应用。下表列出了典型粉末冶金不锈钢的化学成分，其中化学成分为重量百分比：种类 Cf Mo Si At the same time, due to the existence of pores inside the powder metallurgy stainless steel, its mechanical properties and corrosion resistance are inferior to those of dense stainless steel, which greatly limits its application. The table below lists the chemical composition of typical powder metallurgy stainless steels, where the chemical composition is weight percent: Type Cf Mo Si

SS- : (相当于 S S¾>〉 ! S-20 H2 - 1.5 < 、 . > . 余量相当于 SU i S) 14 1 .5 <2 余量 l i.5-13.5 · 5 - <i <1 SS- : (equivalent to S S3⁄4>〉 ! S-20 H2 - 1.5 < , . > . The balance is equivalent to SU i S) 14 1 .5 <2 margin l i.5-13.5 · 5 - <i < 1

SS-30(相当于 SLJS410) < ' 余量下表列出了典型粉末冶金不锈钢的物理和力学性能，其中 L代表较低， M 代表中等， H代表较高：密度抗拉强度冲击韧性延伸率硬度孔隙率材料种类 SS-30 (equivalent to SLJS410) < ' Balance The following table lists the physical and mechanical properties of typical powder metallurgy stainless steels, where L stands for lower, M stands for medium, and H stands for higher: density tensile strength impact toughness elongation Hardness porosity material type

(g/ cm³) (MPa) (J/cm²) (%) (HV) (%) (g/ cm ³ ) (MPa) (J/cm ² ) (%) (HV) (%)

L 6.4' -6.7 196- -343 30- -50 10- -15 50-80 16-19 L 6.4' -6.7 196- -343 30- -50 10- -15 50-80 16-19

SS-10 M 6.7' -7.0 343- -441 50- -60 15- -25 70-140 12-16 SS-10 M 6.7' -7.0 343- -441 50- -60 15- -25 70-140 12-16

H 7.0 ~1A 392- -441 50- -60 25- -30 80-140 7-12 H 7.0 ~1A 392- -441 50- -60 25- -30 80-140 7-12

L 6.4' -6.7 196- -343 30- -50 10- -15 50-80 16-20 L 6.4' -6.7 196- -343 30- -50 10- -15 50-80 16-20

SS-20 M 6.7' -7.0 343- -441 50- -60 15- -25 70-140 12-16 SS-20 M 6.7' -7.0 343- -441 50- -60 15- -25 70-140 12-16

H 7.0 -7.4 392- -441 50- -60 25- -30 80-140 7-12 H 7.0 -7.4 392- -441 50- -60 25- -30 80-140 7-12

L 6.5' -6.7 245- -343 30- -50 10- -15 60-100 14-16L 6.5' -6.7 245- -343 30- -50 10- -15 60-100 14-16

SS-30 SS-30

M 6.7' -7.0 294- -392 50- -60 15- -25 60-140 10-14 下表列出了典型粉末冶金不锈钢的耐腐蚀性能，其中耐蚀性是粉末冶金不锈钢在水中浸泡 24h的生锈情况表示的：

发明内容 M 6.7' -7.0 294- -392 50- -60 15- -25 60-140 10-14 The following table lists the corrosion resistance of typical powder metallurgy stainless steels, where corrosion resistance is the soaking of powder metallurgy stainless steel in water for 24 h. Represented by rust:

Summary of the invention

本发明主要解决的技术问题是提供一种高性能粉末冶金不锈钢及其制备方法，能得到具有极佳的耐腐蚀性、抗氧化性、较佳的综合力学性能的高性能粉末冶金不锈钢。 The technical problem to be solved by the present invention is to provide a high-performance powder metallurgy stainless steel and a preparation method thereof, which can obtain a high-performance powder with excellent corrosion resistance, oxidation resistance and better comprehensive mechanical properties. Metallurgical stainless steel.

为解决上述技术问题，本发明釆用的一个技术方案是：提供一种高性能粉末冶金不锈钢，以重量百分比计的组成成分为： 316L奥氏体不锈钢 92.5-97.0%、 FeB 0.5-1.5%、 FeMo60 1-3%、 TiC 1-3%。 In order to solve the above technical problems, one technical solution adopted by the present invention is: Providing a high performance powder metallurgy stainless steel, the composition of which is in weight percentage: 316L austenitic stainless steel 92.5-97.0%, FeB 0.5-1.5%, FeMo60 1-3%, TiC 1-3%.

在本发明一个较佳实施例中，所述的高性能粉末冶金不锈钢以重量百分比计的组成成分为： 316L奥氏体不锈钢 95.5%、 FeB 1%, FeMo60 2%、 TiC 1.5%。 In a preferred embodiment of the invention, the high performance powder metallurgy stainless steel has a composition by weight percentage: 316L austenitic stainless steel 95.5%, FeB 1%, FeMo60 2%, TiC 1.5%.

在本发明一个较佳实施例中，所述 FeMo60中 Mo的重量百分比为 59-61%。在本发明一个较佳实施例中，所述高性能粉末冶金不锈钢的制备方法包括步骤为：将原料 316L奥氏体不锈钢、 FeB、 FeMo60和 TiC进行混料、球磨、压制成型、脱脂、真空烧结，得到高性能粉末冶金不锈钢。 In a preferred embodiment of the invention, the weight percentage of Mo in the FeMo60 is 59-61%. In a preferred embodiment of the present invention, the method for preparing the high performance powder metallurgy stainless steel comprises the steps of: mixing raw material 316L austenitic stainless steel, FeB, FeMo60 and TiC, ball milling, press forming, degreasing, vacuum sintering , get high performance powder metallurgy stainless steel.

在本发明一个较佳实施例中，所述混料和球磨在球磨机中进行，所述球磨机的转速为 160-200 rpm, 所述球磨时间为 3-6小时。 In a preferred embodiment of the invention, the mixing and ball milling are carried out in a ball mill having a rotational speed of 160-200 rpm and a ball milling time of 3-6 hours.

在本发明一个较佳实施例中，所述原料还包括硬脂酸辞，所述硬脂酸辞和所述 316L奥氏体不锈钢、 FeB、 FeMo60、 TiC总质量的质量比为 0.6:100。 In a preferred embodiment of the present invention, the raw material further comprises stearic acid, and the mass ratio of the stearic acid and the 316L austenitic stainless steel, FeB, FeMo60, TiC is 0.6:100.

在本发明一个较佳实施例中，所述压制的压力为 600-750MPa。 In a preferred embodiment of the invention, the pressing pressure is from 600 to 750 MPa.

在本发明一个较佳实施例中，所述脱脂的过程是在真空度高于 10Pa的真空炉中进行的，升温过程为在室温到 400 °C之间的升温速度为 0.7-1.0°C/min,在 400 °C-550°C之间的升温速度为 1.5-2.0 °C/min, 在 550°C下保温 60-80min。 In a preferred embodiment of the present invention, the degreasing process is carried out in a vacuum furnace having a degree of vacuum higher than 10 Pa, and the temperature rising process is a temperature increase rate between room temperature and 400 ° C of 0.7-1.0 ° C / Min, the heating rate between 400 ° C and 550 ° C is 1.5-2.0 ° C / min, and the temperature is maintained at 550 ° C for 60-80 min.

在本发明一个较佳实施例中，所述真空烧结的过程是在真空度高于 O.lPa的真空烧结炉中进行的，升温过程为在室温到 1120 °C之间的升温速度为 10°C/min, 在 1120 °C下保温 60min,在 1120 °C到终烧温度的升温速率为 5°C/min,在所述终烧温度下保温 50-80min, 所述终烧温度为 1230-1270°C , 所述真空烧结后的降温过程中的降温速度大于 5°C/min。在本发明一个较佳实施例中，所述终烧温度为 1250°C , 在 1250°C下保温时间为 60min。本发明的有益效果是：本发明的高性能粉末冶金不锈钢及其制备方法，加入烧结助剂和强化相，使致密度得到极大的提高，在保持其优良的耐腐蚀性的同时，力学性能得到明显的改善，可以用于制造承受一定负荷及对耐腐蚀性和抗氧化性有较高要求的设备或部件，在机械、化工、石油、海洋、轻工等多种领域都具有广泛的应用前景。具体实施方式 In a preferred embodiment of the present invention, the vacuum sintering process is carried out in a vacuum sintering furnace having a vacuum degree higher than 0.1 Pa, and the temperature rising process is a temperature rising rate of 10 ° between room temperature and 1120 ° C. C/min, incubated at 1120 ° C for 60 min, the heating rate at 1120 ° C to the final firing temperature is 5 ° C / min, at the final firing temperature for 50-80 min, the final firing temperature is 1230- 1270 ° C, the cooling after the vacuum sintering The cooling rate during the process is greater than 5 ° C / min. In a preferred embodiment of the invention, the final firing temperature is 1250 ° C and the holding time is 12 min at 1250 ° C. The invention has the beneficial effects that: the high-performance powder metallurgy stainless steel of the invention and the preparation method thereof, the sintering aid and the strengthening phase are added, the density is greatly improved, and the mechanical properties are maintained while maintaining the excellent corrosion resistance. Significant improvement, can be used to manufacture equipment or components that bear a certain load and have high requirements for corrosion resistance and oxidation resistance. It is widely used in various fields such as machinery, chemical industry, petroleum, marine, light industry, etc. prospect. detailed description

下面将对本发明实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例仅是本发明的一部分实施例，而不是全部的实施例。基于本发明中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其它实施例，都属于本发明保护的范围。实施例一：提供一种高性能粉末冶金不锈钢，以重量百分比计的组成成分为： 316L奥氏体不锈钢 92.5%、 FeB 1.5%、 FeMo60 3%、 TiC 3%。实施例二：提供一种高性能粉末冶金不锈钢，以重量百分比计的组成成分为： 316L奥氏体不銹钢 94.5%、 FeB 1.5%、 FeMo60 3%、 TiC 1%。实施例三：提供一种高性能粉末冶金不锈钢，以重量百分比计的组成成分为： 316L奥氏体不銹钢 95.5%、 FeB 1%、 FeMo60 2%、 TiC 1.5%。实施例四：提供一种高性能粉末冶金不锈钢，以重量百分比计的组成成分为： 316L奥氏体不锈钢 97%、 FeB 0.5%、 FeMo60 1%、 TiC 1.5%。实施例五：提供一种高性能粉末冶金不锈钢的制备方法，包括步骤为： ( 1 )分别按照实施例一至四中的组成成分以粉末的形式配制混料，混料工序在行星式球磨机中进行，球磨机转速为 160rpm, 时间为 6h, 且在每 100g混合粉末中加入 0.6g硬脂酸辞作润滑剂，其中硬脂酸辞作为润滑剂，能减緩压制过程中粉末之间及粉末与模壁之间的摩擦，减小脱模压力和提高压坯密度； The technical solutions in the embodiments of the present invention will be clearly and completely described below. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention. Example 1: A high performance powder metallurgy stainless steel is provided. The composition by weight percentage is: 316L austenitic stainless steel 92.5%, FeB 1.5%, FeMo60 3%, TiC 3%. Example 2: A high performance powder metallurgy stainless steel is provided. The composition by weight percentage is: 316L austenitic stainless steel 94.5%, FeB 1.5%, FeMo60 3%, TiC 1%. Example 3: A high performance powder metallurgy stainless steel is provided. The composition by weight percentage is: 316L austenitic stainless steel 95.5%, FeB 1%, FeMo60 2%, TiC 1.5%. Embodiment 4: A high performance powder metallurgy stainless steel is provided, and the composition by weight percentage is: 316L austenitic stainless steel 97%, FeB 0.5%, FeMo60 1%, TiC 1.5%. Embodiment 5: A method for preparing a high performance powder metallurgy stainless steel is provided, comprising the steps of: (1) preparing a mixture in the form of a powder according to the components in Embodiments 1 to 4, respectively, and the mixing step is carried out in a planetary ball mill. The ball mill rotates at 160 rpm for 6 hours, and 0.6 g of stearic acid is added as a lubricant per 100 g of mixed powder. The stearic acid is used as a lubricant to slow the powder and the powder and the mold during the pressing process. Friction between walls, reducing demolding pressure and increasing compact density;

( 2 )将粉末压制成型，压制成型时所用的压力为 600MPa; ( 3 )脱脂工序在真空度高于 10Pa的条件下进行，在室温〜 400°C之间的升温速度为 0.7°C/min, 在 400 ~ 550°C之间的升温速度为 2.0°C/min, 在 550°C保温 80min; (2) The powder is press-formed, and the pressure used in the press forming is 600 MPa; (3) the degreasing step is carried out under the condition that the degree of vacuum is higher than 10 Pa, and the temperature rising rate between room temperature and 400 ° C is 0.7 ° C/min. , the heating rate between 400 ~ 550 ° C is 2.0 ° C / min, incubated at 550 ° C for 80 min;

( 4 )在真空烧结炉中进行真空烧结，真空度高于 O.lPa, 室温到 1120°C的加热速率为 l0°C/min,在 1120°(保温601^11, 1120°C〜终烧温度的加热速率为 5 °C/min, 终烧温度为 1230°C , 保温时间为 80min, 降温过程中的降温速率最好大于 5°C/min。在上述制备工艺条件下，不同成分配比的烧结不锈钢的主要性能见下表: (4) Vacuum sintering in a vacuum sintering furnace, the vacuum degree is higher than 0.1 Pa, the heating rate from room temperature to 1120 ° C is l0 ° C / min, at 1120 ° (insulation 601 ^ 11 , 1120 ° C ~ final burning The heating rate of the temperature is 5 °C/min, the final firing temperature is 1230 °C, the holding time is 80 min, and the cooling rate during the cooling process is preferably greater than 5 ° C / min. Under the above preparation conditions, the different distribution ratios The main properties of sintered stainless steel are shown in the following table:

实施例六：提供一种高性能粉末冶金不锈钢的制备方法，包括步骤为： (1 )分别按照实施例一至四中的组成成分以粉末的形式配制混料，混料工序在行星式球磨机中进行，球磨机转速为 180 rpm, 时间为 5h, 且在每 100g混合粉末中加入 0.6g硬脂酸辞作润滑剂；

Embodiment 6: Providing a method for preparing a high performance powder metallurgy stainless steel, comprising the steps of: (1) The mixture was prepared in the form of a powder according to the compositions of Examples 1 to 4, respectively, and the mixing process was carried out in a planetary ball mill at a rotation speed of 180 rpm for 5 hours, and 0.6 was added per 100 g of the mixed powder. g stearic acid is used as a lubricant;

(2)将粉末压制成型，压制成型时所用的压力为 650MPa; (2) The powder is press-formed, and the pressure used in press molding is 650 MPa;

(3)脱脂工序在真空度高于 10Pa的条件下进行，在室温〜 400 °C之间的升温速度为 0.8°C/min, 在 400 ~ 550°C之间的升温速度为 1.8°C/min, 在 550 °C保温 70min; (3) The degreasing step is carried out under the condition that the degree of vacuum is higher than 10 Pa, the temperature rising rate between room temperature and 400 ° C is 0.8 ° C / min, and the temperature rising rate between 400 ° 550 ° C is 1.8 ° C / Min, kept at 550 °C for 70min;

(4)在真空烧结炉中进行真空烧结，真空度高于 O.lPa, 室温到 1120°C的加热速率为 l0°C/min,在 1120°(保温601^11, 1120°C〜终烧温度的加热速率为 5 °C/min, 终烧温度为 1250 °C, 保温时间为 70min, 降温过程中的降温速率最好大于 5°C/min。 (4) Vacuum sintering in a vacuum sintering furnace, the degree of vacuum is higher than 0.1 Pa, the heating rate from room temperature to 1120 ° C is l0 ° C / min, at 1120 ° (insulation 601 ^ 11 , 1120 ° C ~ final burning The heating rate of the temperature is 5 °C/min, the final burning temperature is 1250 °C, the holding time is 70 min, and the cooling rate during the cooling process is preferably greater than 5 °C/min.

在上述制备工艺条件下，不同成分配比的烧结不锈钢的主要性能见下表： Under the above preparation conditions, the main properties of sintered stainless steel with different distribution ratios are as follows:

实施例七： Example 7:

提供一种高性能粉末冶金不锈钢的制备方法，包括步骤为： A method for preparing a high performance powder metallurgy stainless steel is provided, the steps comprising:

(1 )分别按照实施例一至四中的组成成分以粉末的形式配制混料，混料工序在行星式球磨机中进行，球磨机转速为 200 rpm, 时间为 4h, 且在每 100g混合粉末中加入 0.6g硬脂酸辞作润滑剂； (1) The mixture was prepared in the form of a powder according to the compositions of Examples 1 to 4, respectively, and the mixing process was carried out in a planetary ball mill at a rotation speed of 200 rpm for 4 hours, and 0.6 was added per 100 g of the mixed powder. g stearic acid is used as a lubricant;

(2)将粉末压制成型，压制成型时所用的压力为 700MPa; (3)脱脂工序在真空度高于 10Pa的条件下进行，在室温〜 400 °C之间的升温速度为 0.9°C/min, 在 400 ~ 550°C之间的升温速度为 1.5°C/min, 在 550 °C保温 60min; (2) press molding the powder, the pressure used in press molding is 700 MPa; (3) The degreasing step is carried out under the condition that the degree of vacuum is higher than 10 Pa, the temperature rising rate between room temperature and 400 ° C is 0.9 ° C / min, and the temperature rising rate between 400 and 550 ° C is 1.5 ° C / Min, kept at 550 °C for 60 min;

(4)在真空烧结炉中进行真空烧结，真空度高于 O.lPa; 室温到 1120°C的加热速率为 lO°C/min,在 1120°(保温601^11, 1120°C〜终烧温度的加热速率为 5 °C/min, 终烧温度为 1270 °C, 保温时间为 60min, 降温过程中的降温速率最好大于 5°C/min。 (4) Vacuum sintering in a vacuum sintering furnace, the degree of vacuum is higher than 0.1 Pa; the heating rate from room temperature to 1120 ° C is 10 ° C / min, at 1120 ° (insulation 601 ^ 11, 1120 ° C ~ final burning The heating rate of the temperature is 5 °C/min, the final burning temperature is 1270 °C, the holding time is 60 min, and the cooling rate during the cooling process is preferably greater than 5 °C/min.

在上述制备工艺条件下，不同成分配比的烧结不锈钢的主要性能见下表: Under the above preparation conditions, the main properties of sintered stainless steel with different distribution ratios are as follows:

实施例八: Example 8:

(1 )分别按照实施例一至四中的组成成分以粉末的形式配制混料，混料工序在行星式球磨机中进行，球磨机转速为 200 rpm, 时间为 3 h, 且在每 100g混合粉末中加入 0.6g硬脂酸辞作润滑剂； (1) The mixture was prepared in the form of a powder according to the compositions of Examples 1 to 4, respectively, and the mixing process was carried out in a planetary ball mill at a rotation speed of 200 rpm for 3 hours, and added per 100 g of the mixed powder. 0.6g stearic acid is used as a lubricant;

(2)将粉末压制成型，压制成型时所用的压力为 750MPa; (2) The powder is press-formed, and the pressure used in the press forming is 750 MPa;

(3)脱脂工序在真空度高于 10Pa的条件下进行，在室温〜 400 °C之间的升温速度为 1.0°C/min, 在 200 ~ 550 °C之间的升温速度为 1.5°C/min, 在 550 °C保温 60min; (3) The degreasing step is carried out under conditions of a vacuum of more than 10 Pa, a heating rate of 1.0 ° C/min between room temperature and 400 ° C, and a heating rate of 1.5 ° C between 200 and 550 ° C. Min, kept at 550 °C for 60 min;

(4)在真空烧结炉中进行真空烧结，真空度高于 O.lPa, 室温到 1120°C的加热速率为 lO°C/min; 在 1120°(保温601^11, 1120°C〜终烧温度的加热速率为 5 °C/min, 终烧温度为 1270 °C , 保温时间为 50min, 降温过程中的降温速率最好大于 5°C/min。 (4) Vacuum sintering in a vacuum sintering furnace, the degree of vacuum is higher than 0.1 Pa, room temperature to 1120 ° C The heating rate is 10 ° C / min; at 1120 ° (insulation 601 ^ 11 , 1120 ° C ~ final firing temperature of 5 ° C / min, the final firing temperature of 1270 ° C, holding time of 50 min, cooling process The cooling rate in the medium is preferably greater than 5 ° C / min.

研究表明，几乎所有的粉末冶金不锈钢的性能都随着密度的增大而提高，并且适量强化相的加入和形成还会进一步提高材料的力学性能。在粉末冶金 316L 不锈钢的基础上，加入烧结助剂和强化相，使致密度得到极大的提高，保持其优良的耐腐蚀性的同时，力学性能得到明显的改善。 Studies have shown that the performance of almost all powder metallurgy stainless steels increases with increasing density, and the addition and formation of an appropriate amount of strengthening phase further enhances the mechanical properties of the material. On the basis of powder metallurgy 316L stainless steel, sintering aid and strengthening phase are added to greatly increase the density, while maintaining its excellent corrosion resistance, the mechanical properties are obviously improved.

所述高性能粉末冶金不锈钢中加入了适量的的 FeB和 FeMo。 FeB和 FeMo 的加入使材料在升温过程中顺序发生如下反应： An appropriate amount of FeB and FeMo are added to the high performance powder metallurgy stainless steel. The addition of FeB and FeMo causes the material to react in sequence during the heating process:

Fe+FeB→Fe₂B; Fe+FeB→Fe ₂ B;

FeMo+FeB→Mo₂FeB₂+Fe; FeMo+FeB→Mo ₂ FeB ₂ +Fe;

FeMo+Fe₂B→Mo₂FeB₂+3Fe; FeMo+Fe ₂ B→Mo ₂ FeB ₂ +3Fe;

y-Fe+Fe₂B→液相 (LI); y-Fe+Fe ₂ B→liquid phase (LI);

y-Fe+Ll+Mo₂FeB₂→液相（ L2 ) +Mo₂FeB₂。 y-Fe+Ll+Mo ₂ FeB ₂ →liquid phase (L2) +Mo ₂ FeB ₂ .

经过上述反应，材料在较低的烧结温度下就产生了液相，该液相会偏聚在颗粒接触区和颗粒内的晶界处。该液相对固相颗粒有较好的润湿性，使颗粒发生重排，从而使得烧结体的致密化速率快速提高。同时在晶界处原位生成了弥散分布的 Mo₂FeB₂三元硼化物，可抑制不锈钢烧结过程中晶粒的长大，同时也起到了弥散强化的作用，因而明显提高了烧结不锈钢的致密度和力学性能。另一方面，适量 TiC 的加入也起到了弥散强化和抑制晶粒长大的作用，使该烧结不锈钢的力学性能进一步得以提高。 Through the above reaction, the material produces a liquid phase at a lower sintering temperature, and the liquid phase is segregated at the grain contact zone and the grain boundary within the particle. The liquid has good wettability with respect to the solid phase particles, so that the particles are rearranged, so that the densification rate of the sintered body is rapidly increased. At the same time, a dispersed distribution of Mo ₂ FeB ₂ ternary boride is formed in situ at the grain boundary, which can inhibit the growth of crystal grains during sintering of stainless steel. It acts as a dispersion strengthening, thus significantly increasing the density and mechanical properties of sintered stainless steel. On the other hand, the addition of an appropriate amount of TiC also acts to enhance dispersion and inhibit grain growth, further improving the mechanical properties of the sintered stainless steel.

本发明的提高烧结不锈钢性能的方法，使改性后的烧结不锈钢的致密度 The method for improving the performance of sintered stainless steel of the present invention enables the density of the modified sintered stainless steel

>97.0%, 抗拉强度 ob≥470MPa, 硬度 HV≥200 , 延伸率 δ10≥18%, 冲击韧性 aK>55J/cm², 自腐蚀电位 Ecorr≥-0.3V, 测试过程中试验介质釆用 0.5mol/L的硫酸溶液。它具有极佳的耐腐蚀性、抗氧化性、较佳的综合力学性能，可以用于制造承受一定负荷及对耐腐蚀性和抗氧化性有较高要求的设备或部件，在机械、化工、石油、海洋、轻工等多种领域都具有广泛的应用前景。 >97.0%, tensile strength ob≥470MPa, hardness HV≥200, elongation δ10≥18%, impact toughness aK>55J/cm ² , self-corrosion potential Ecorr≥-0.3V, test medium 0.50.5mol during the test /L sulfuric acid solution. It has excellent corrosion resistance, oxidation resistance, and better comprehensive mechanical properties. It can be used to manufacture equipment or components that are subjected to a certain load and have high requirements for corrosion resistance and oxidation resistance. In machinery, chemical industry, Oil, marine, light industry and other fields have broad application prospects.

当高性能粉末冶金不锈钢中 FeB 的加入量为 1.0wt. % , FeMo60加入量为 2.0wt. % , TiC为 1.5wt. %时，材料的致密度相对较高，材料的强化作用也相对较强，材料的抗拉强度、延伸率和冲击韧性也相对较高，其自腐蚀电位也相对较高。在制备工艺参数中，烧结温度和保温时间对性能的影响相对较大，当烧结温度为 1250°C , 保温时间为 60min时，材料的综合力学性能和耐蚀性均相对较高。以上所述仅为本发明的实施例，并非因此限制本发明的专利范围，凡是利用本发明说明书内容所作的等效结构或等效流程变换，或直接或间接运用在其它相关的技术领域，均同理包括在本发明的专利保护范围内。 When the amount of FeB added in the high performance powder metallurgy stainless steel is 1.0wt.%, the amount of FeMo60 added is 2.0wt.%, and the TiC is 1.5wt.%, the density of the material is relatively high, and the strengthening effect of the material is relatively strong. The tensile strength, elongation and impact toughness of the material are also relatively high, and the self-corrosion potential is relatively high. In the preparation process parameters, the sintering temperature and holding time have a relatively large effect on the performance. When the sintering temperature is 1250 ° C and the holding time is 60 min, the comprehensive mechanical properties and corrosion resistance of the materials are relatively high. The above is only the embodiment of the present invention, and thus does not limit the scope of the invention, and the equivalent structure or equivalent process transformation made by using the content of the specification of the present invention, or directly or indirectly applied to other related technical fields, The same is included in the scope of patent protection of the present invention.

Claims

权利要求书 Claim

1、一种高性能粉末冶金不锈钢，其特征在于，以重量百分比计的组成成分为： 316L奥氏体不锈钢 92.5-97.0%、 FeB 0.5-1.5%、 FeMo60 1-3%、 TiC 1-3%。 1. A high performance powder metallurgy stainless steel characterized in that the composition by weight percentage is: 316L austenitic stainless steel 92.5-97.0%, FeB 0.5-1.5%, FeMo60 1-3%, TiC 1-3% .

2、根据权利要求 1所述的高性能粉末冶金不锈钢，其特征在于，以重量百分比计的组成成分为： 316L奥氏体不锈钢 95.5%、 FeB 1%, FeMo60 2%、 TiC 2. The high performance powder metallurgy stainless steel according to claim 1, wherein the composition by weight percentage is: 316L austenitic stainless steel 95.5%, FeB 1%, FeMo60 2%, TiC

1.5%。 1.5%.

3、根据权利要求 1或 2所述的高性能粉末冶金不锈钢，其特征在于，所述 FeMo60中 Mo的重量百分比为 59-61%。 The high performance powder metallurgy stainless steel according to claim 1 or 2, wherein the FeMo60 has a weight percentage of Mo of 59-61%.

4、根据权利要求 1所述的高性能粉末冶金不锈钢的制备方法，其特征在于，包括步骤为：将原料 316L奥氏体不锈钢、 FeB、 FeMo60和 TiC进行混料、球磨、压制成型、脱脂、真空烧结，得到高性能粉末冶金不锈钢。 The method for preparing a high performance powder metallurgy stainless steel according to claim 1, comprising the steps of: mixing, pulverizing, press forming, degreasing, a raw material 316L austenitic stainless steel, FeB, FeMo60 and TiC, Vacuum sintering gives high performance powder metallurgy stainless steel.

5、根据权利要求 4所述的制备方法，其特征在于，所述混料和球磨在球磨机中进行，所述球磨机的转速为 160-200 rpm, 所述球磨时间为 3-6小时。 The preparation method according to claim 4, wherein the mixing and ball milling are carried out in a ball mill, the ball mill has a rotation speed of 160 to 200 rpm, and the ball milling time is 3 to 6 hours.

6、根据权利要求 4所述的制备方法，其特征在于，所述原料还包括硬脂酸辞，所述硬脂酸辞和所述 316L奥氏体不锈钢、 FeB、 FeMo60、 TiC总质量的质量比为 0.6:100。 The preparation method according to claim 4, wherein the raw material further comprises stearic acid, the stearic acid and the total mass of the 316L austenitic stainless steel, FeB, FeMo60, and TiC. The ratio is 0.6:100.

7、根据权利要求 4 所述的制备方法，其特征在于，所述压制的压力为 600-750MPa„ 7. The preparation method according to claim 4, wherein the pressing pressure is 600-750 MPa.

8、根据权利要求 4所述的制备方法，其特征在于，所述脱脂的过程是在真空度高于 10Pa的真空炉中进行的，升温过程为在室温到 400°C之间的升温速度为 0.7-1.0°C/min, 在 400°C-550°C之间的升温速度为 1.5-2.0°C/min, 在 550°C下保温 60-80min。 The preparation method according to claim 4, wherein the degreasing process is performed in a vacuum furnace having a degree of vacuum higher than 10 Pa, and the temperature rising process is a temperature rising rate between room temperature and 400 ° C. 0.7-1.0 ° C / min, the temperature increase rate between 400 ° C and 550 ° C is 1.5-2.0 ° C / min, and incubated at 550 ° C for 60-80 min.

9、根据权利要求 4所述的制备方法，其特征在于，所述真空烧结的过程是在真空度高于 O.lPa的真空烧结炉中进行的，升温过程为在室温到 1120°C之间的升温速度为 10°C/min, 在 1120°C下保温 60min, 在 1120°C到终烧温度的升温速率为 5°C/min, 在所述终烧温度下保温 50-80min, 所述终烧温度为 1230-1270 °C, 所述真空烧结后的降温过程中的降温速度大于 5°C/min。 The preparation method according to claim 4, wherein the vacuum sintering process is performed in a vacuum sintering furnace having a vacuum degree higher than 0.1 Pa, and the temperature rising process is between room temperature and 1120 ° C. The heating rate is 10 ° C / min, the temperature is maintained at 1120 ° C for 60 min, the heating rate at 1120 ° C to the final firing temperature is 5 ° C / min, and the temperature is maintained at the final firing temperature for 50-80 min, The final burning temperature is 1230-1270 °C, the cooling rate during the cooling process after the vacuum sintering is greater than 5 ° C / min.

10、根据权利要求 9所述的制备方法，其特征在于，所述终烧温度为 1250 °C, 在 1250°C下保温时间为 60min。 10. The preparation method according to claim 9, wherein the final firing temperature is 1250 ° C, and the holding time at 1250 ° C is 60 min.