CN114318210B - Method for improving corrosion resistance and carburized layer depth of austenitic stainless steel after carburization - Google Patents
Method for improving corrosion resistance and carburized layer depth of austenitic stainless steel after carburization Download PDFInfo
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Abstract
The invention provides a method for improving corrosion resistance and carburized layer depth of austenitic stainless steel after carburization, which comprises the following steps: performing low-pressure vacuum carburization treatment on the pretreated austenitic stainless steel in a vacuum furnace, wherein the carburization temperature is 300-1200 ℃, the heat preservation time is 0.5-24 h, and then performing oil cooling; and (3) carrying out heat treatment on the carburized austenitic stainless steel at the temperature of 600-1300 ℃ for 0.2-24 h, and then carrying out water cooling. The method for improving the corrosion resistance and the carburized layer depth of the austenitic stainless steel after carburization provided by the invention has a short process period, can increase the effective hardened layer depth of the austenitic stainless steel, and improves the corrosion resistance of the carburized austenitic stainless steel.
Description
Technical Field
The invention relates to the technical field of stainless steel strengthening, in particular to a method for improving corrosion resistance and carburized layer depth of austenitic stainless steel after carburization.
Background
The austenitic stainless steel has good corrosion resistance, heat resistance and weldability, and is widely applied to the fields of nuclear power, energy, aviation, navigation and the like. However, austenitic stainless steel has a low carbon content, resulting in poor surface hardness and wear resistance. Further, it has not been possible to surface-strengthen austenitic stainless steel by heat treatment, which has restricted the use thereof.
In order to improve the surface hardness of the austenitic stainless steel and not reduce the corrosion resistance of the austenitic stainless steel, a plurality of methods for strengthening the surface of the austenitic stainless steel are provided at present, such as low-temperature gas carburization (CN 102828145A), glow ion carburization (CN 105603359A) and ion nitriding (CN 111910146A), and the like, but the methods still have the problems of long process period, shallow depth of a carburized layer, obviously reduced corrosion resistance of the carburized surface and the like.
The low-pressure vacuum carburization treatment is also a common austenitic stainless steel surface strengthening method, and can obtain higher surface hardness and effective hardened layer depth in a shorter time. However, the high treatment temperature of low-pressure vacuum carburization causes chromium-rich carbides to be precipitated from the carburized layer of austenitic stainless steel, thereby reducing the corrosion resistance of the austenitic stainless steel.
Therefore, it is important to develop a method for improving the corrosion resistance of austenitic stainless steel after carburization and increasing the depth of the carburized layer.
Disclosure of Invention
The invention aims to solve the technical problem of providing a method for improving the corrosion resistance and the depth of a carburized layer of austenitic stainless steel after carburization, which has simple process and short treatment period.
In order to solve the technical problems, the invention provides a method for improving the corrosion resistance and the depth of a carburized layer of austenitic stainless steel after carburization, which comprises the following steps:
carrying out low-pressure vacuum carburization treatment on the pretreated austenitic stainless steel in a vacuum furnace, wherein the carburization temperature is 300-1200 ℃, the heat preservation time is 0.5-24 h, and then carrying out oil cooling;
and (3) carrying out heat treatment on the carburized austenitic stainless steel at the temperature of 600-1300 ℃ for 0.2-24 h, and then cooling with water.
Further, the austenitic stainless steel low-pressure vacuum carburization treatment is to input high-purity C into a vacuum furnace 2 H 2 Carburizing is performed.
Further, the pressure in the vacuum furnace during the low-pressure vacuum carburization treatment is controlled to be 50-350 Pa.
Further, a carburized layer of 20 to 300 μm is formed on the surface of the austenitic stainless steel after carburization.
Further, the carburizing treatment of the austenitic stainless steel comprises three processes of a soaking period, a carburizing period and a diffusion period, and the two processes of the carburizing period and the diffusion period are circulated until the carbon concentration on the surface of the austenitic stainless steel meets the requirement.
Further, the pressure in the vacuum furnace in the carburizing period is controlled to be 50-150 Pa, and the pressure in the vacuum furnace in the diffusion period is controlled to be 150-350 Pa.
Further, the heat treatment of the austenitic stainless steel after carburization is performed in a tube furnace.
Further, the austenitic stainless steel is pretreated by grinding and polishing the surface of the austenitic stainless steel, and then carrying out ultrasonic cleaning and drying.
The invention provides a method for improving corrosion resistance and carburized layer depth of austenitic stainless steel after carburization, which comprises the steps of firstly carrying out low-pressure vacuum carburization treatment on high-austenitic stainless steel at a lower temperature of 300-1200 ℃, and then carrying out heat treatment on the carburized austenitic stainless steel at a temperature of 600-1300 ℃, so that the austenitic stainless steel can obtain higher surface hardness and effective hardened layer depth after the low-pressure vacuum carburization treatment, and chromium-rich carbide precipitated from a carburized layer of the austenitic stainless steel can be redissolved through subsequent heat treatment, thereby improving the corrosion resistance of the carburized austenitic stainless steel. Meanwhile, the method for improving the corrosion resistance and the depth of the carburized layer of the austenitic stainless steel after carburization only needs two processes of low-pressure vacuum carburization and heat treatment, and has the advantages of simple process and short treatment period.
Drawings
FIG. 1 is a process diagram of 304 austenitic stainless steel and 316L austenitic stainless steel treatment in a method for improving corrosion resistance and depth of carburized layer after carburization of austenitic stainless steel according to the first and second embodiments of the present invention;
FIG. 2 is a graph comparing the hardness change curves of 304 austenitic stainless steel and 316L austenitic stainless steel after treatment in the method for improving corrosion resistance and depth of carburized layer after carburization of austenitic stainless steel according to the first and second examples of the present invention with the hardness change curves of the 304 austenitic stainless steel and 316L austenitic stainless steel after treatment in the first and second comparative examples;
fig. 3 is a graph comparing polarization curves of 304 austenitic stainless steel and 316L austenitic stainless steel after treatment in the method for improving corrosion resistance and depth of carburized layer after carburization of austenitic stainless steel according to the first embodiment and the second embodiment of the present invention with polarization curves of 304 austenitic stainless steel and 316L austenitic stainless steel after treatment in the first comparative embodiment and the second comparative embodiment.
Detailed Description
Referring to fig. 1, the method for improving the corrosion resistance and the depth of the carburized layer of the austenitic stainless steel after carburization provided by the embodiment of the invention comprises the following steps:
step 1) setting the carburizing temperature and the heat preservation time of the austenitic stainless steel according to the chemical components of the austenitic stainless steel. Specifically, the pretreated austenitic stainless steel is subjected to low-pressure vacuum carburization treatment in a vacuum furnace, the carburization temperature is set to 300-1200 ℃, the heat preservation time is controlled to be 0.5-24 h, and then oil cooling is carried out. Wherein, the pressure intensity in the vacuum furnace is controlled between 50Pa and 350Pa during the low-pressure vacuum carburization treatment.
The carburizing treatment of the austenitic stainless steel comprises three processes of a soaking period, a carburizing period and a diffusion period, and the two processes of the carburizing period and the diffusion period are circulated until the carbon concentration on the surface of the austenitic stainless steel meets the requirement.
Wherein the pressure in the vacuum furnace in the carburizing period is controlled to be 50-150 Pa, and the pressure in the vacuum furnace in the diffusion period is controlled to be 150-350 Pa.
In one embodiment of the present invention, the low-pressure vacuum carburization of austenitic stainless steel is performed by introducing high-purity C into a vacuum furnace 2 H 2 Carburizing is performed. After the carburization treatment is finished, a carburized layer with the thickness of 20-300 mu m can be formed on the surface of the austenitic stainless steel.
And 2) carrying out heat treatment on the carburized austenitic stainless steel, and controlling the heat treatment temperature and the heat preservation time according to the dissolution temperature of carbides in the carburized layer, wherein the heat treatment temperature is set to 600-1300 ℃, and the heat preservation time is controlled to 0.2-24 h.
In one embodiment of the present invention, the heat treatment of the austenitic stainless steel after carburization is performed in a tube furnace.
The pretreatment of the austenitic stainless steel comprises the steps of mechanically grinding the surface of the austenitic stainless steel, polishing the austenitic stainless steel by using polishing paste, ultrasonically cleaning the austenitic stainless steel in absolute ethyl alcohol, and finally drying the austenitic stainless steel.
The method for improving the corrosion resistance and the depth of carburized layer of austenitic stainless steel provided by the present invention after carburization will be specifically described by the following examples and comparative examples.
Example one
In this embodiment, 304 austenitic stainless steel is taken as an example to illustrate a method for improving corrosion resistance and depth of carburized layer of austenitic stainless steel provided by the present invention after carburization, which specifically comprises the following steps:
1. the method comprises the following steps of taking 304 austenitic stainless steel, mechanically grinding the surface of the stainless steel according to a standard process, polishing the stainless steel by diamond polishing paste with the particle size of 2.5 mu m, cleaning the stainless steel by ultrasonic waves in absolute ethyl alcohol, and drying the stainless steel for later use. Wherein, the chemical components of the 304 austenitic stainless steel are, by mass, 0.07% of C, 0.43% of Si, 1.15% of Mn, 8.17% of Ni, 18.36% of Cr, and the balance of Fe and inevitable impurities.
2. And (3) loading the 304 austenitic stainless steel treated in the step one into a vacuum furnace for low-pressure vacuum carburization, starting heating after vacuumizing, raising the temperature in the furnace to 750 ℃, and preserving heat for a certain time to ensure that all parts in the vacuum furnace are uniformly heated. Then high-purity C is input into the vacuum furnace 2 H 2 Carburizing is carried out, and the air pressure in the vacuum furnace is controlled to be 300Pa during the carburizing period. After carburizing for a certain time, suspending high-purity C 2 H 2 The 304 austenitic stainless steel enters a diffusion stage, and the air pressure in the vacuum furnace is controlled to be 70Pa in the diffusion stage. After the diffusion is sufficient, the circulation of two processes of the carburizing period and the diffusion period of the next period is carried out, in order to ensure that the 304 austenitic stainless steel is fully carburized and achieve good carburizing effect, the two processes of the carburizing period and the diffusion period are circulated according to the method until the carbon concentration on the surface of the 304 austenitic stainless steel reaches the requirement,the final total carburization process took 2.6 hours. And then putting the 304 austenitic stainless steel after carburization into quenching oil for cooling.
3. And (4) putting the 304 austenitic stainless steel subjected to carburization treatment in the step two into a tube furnace for heat treatment, heating the 304 austenitic stainless steel to 950 ℃ and keeping the temperature for 0.7h, then cooling by water, and then taking out. The 304 austenitic stainless steel obtained in this embodiment is abbreviated as 304CT-HT, and the specific processing process is shown in fig. 1.
Comparative example 1
The comparison example is different from the first example in that the heat treatment of the third step of the first example is not performed, and the other steps are the same as the first example, and 304 austenitic stainless steel obtained by the comparison example is abbreviated as 304CT.
Example two
In this embodiment, a 316L austenitic stainless steel is taken as an example to illustrate a method for improving corrosion resistance and carburized layer depth of an austenitic stainless steel after carburization provided by the present invention, which is specifically performed according to the following steps:
1. taking 316L austenitic stainless steel, mechanically grinding the surface of the austenitic stainless steel according to a standard process, polishing the austenitic stainless steel by diamond polishing paste with the particle size of 2.5 mu m, then cleaning the austenitic stainless steel by ultrasonic waves in absolute ethyl alcohol, and then drying the austenitic stainless steel for later use. Wherein, the chemical components of the 316L austenitic stainless steel comprise, by mass, 0.028% of C, 0.93% of Si, 1.88% of Mn, 10.8% of Ni, 17.2% of Cr, 2.01% of Mo, and the balance of Fe and inevitable impurities.
2. And (3) loading the 316L austenitic stainless steel treated in the step one into a vacuum furnace for low-pressure vacuum carburization, starting heating after vacuumizing, raising the temperature in the furnace to 750 ℃, and preserving heat for a certain time to ensure that all parts in the vacuum furnace are uniformly heated. Then high-purity C is input into the vacuum furnace 2 H 2 Carburizing is carried out, and the air pressure in the vacuum furnace is controlled to be 300Pa during the carburizing period. After carburizing for a certain time, suspending high-purity C 2 H 2 The 316L austenitic stainless steel is led to enter a diffusion stage, and the air pressure in the vacuum furnace is controlled to be 70Pa in the diffusion stage. After the diffusion is sufficient, the cycle of two processes of the carburizing period and the diffusion period of the next period is carried outIn order to fully carburize the 316L austenitic stainless steel and achieve good carburization effect, the two processes of the carburization period and the diffusion period are circulated according to the method until the surface carbon concentration of the 316L austenitic stainless steel reaches the requirement, and finally the total carburization process takes 2.6 hours. And then putting the 316L austenitic stainless steel after carburization into quenching oil for cooling.
3. And (3) putting the 316L austenitic stainless steel subjected to carburization treatment in the step two into a tube furnace for heat treatment, heating the 316L austenitic stainless steel to 950 ℃ and keeping the temperature for 0.7h, then cooling by water, and then taking out. The 316L austenitic stainless steel obtained in the embodiment is called 316L CT-HT for short, and the specific treatment process is shown in FIG. 1.
Comparative example No. two
The present comparative example is different from the second example in that the heat treatment of the third step of the second example is not performed, and the same as the second example, the 316L austenitic stainless steel obtained by the present comparative example is abbreviated as 316L CT.
The effective hardened layer depth can reflect the real mechanical property of the carburized workpiece to a certain degree, and is one of important indexes for evaluating whether the carburized workpiece is qualified. According to the regulation in the national standard GB/T9451-2005, the vertical distance from the surface of the test piece to a position 50HV greater than the hardness of the matrix is the effective hardened layer depth. Therefore, the 304 austenitic stainless steel and the 316L austenitic stainless steel in the examples of the present invention and the comparative examples each have a boundary hardness of 320 HV.
Referring to fig. 2, the 304 austenitic stainless steel and the 316L austenitic stainless steel are subjected to heat treatment after carburization treatment, and the effective hardened layer depth thereof is significantly increased and the hardness change is not large. Wherein the 304 austenitic stainless steel is heat treated after the carburizing treatment, the effective hardened layer depth is increased from 49 μm to 95 μm compared with the case where only the carburizing treatment is performed. The 316L austenitic stainless steel was heat treated after the carburization treatment, and the effective depth of hardened layer increased from 60 μm to 110 μm as compared to the case where only the carburization treatment was performed.
Referring to fig. 3, the 304 austenitic stainless steel and the 316L austenitic stainless steel are carburized and then heat treated, and compared with the case of performing only carburization, the self-corrosion potential is significantly improved, and the corrosion current is reduced by an order of magnitude. Therefore, the 304 austenitic stainless steel and the 316L austenitic stainless steel, which are carburized and then heat-treated, have higher corrosion resistance than the 304 austenitic stainless steel and the 316L austenitic stainless steel, which are carburized only, respectively.
Therefore, the method for improving the corrosion resistance and the depth of the carburized layer of the austenitic stainless steel after carburization not only can improve the corrosion resistance of the austenitic stainless steel after carburization, but also can increase the depth of the carburized layer of the austenitic stainless steel after carburization.
Finally, it should be noted that the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting, and although the present invention has been described in detail with reference to examples, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, which should be covered by the claims of the present invention.
Claims (5)
1. A method for improving the corrosion resistance and the depth of a carburized layer of austenitic stainless steel after carburization is characterized by comprising the following steps:
carrying out low-pressure vacuum carburization treatment on the pretreated austenitic stainless steel in a vacuum furnace at 50-350 Pa, wherein the carburization temperature is 750-1200 ℃, the heat preservation time is 0.5-24 h, and then carrying out oil cooling;
carrying out heat treatment on the carburized austenitic stainless steel, wherein the heat treatment temperature is 600-1300 ℃, the heat preservation time is 0.2-24 h, and then carrying out water cooling;
the surface of the austenitic stainless steel forms a carburized layer of 95-300 mu m after carburization and heat treatment.
2. The method for improving the corrosion resistance and the depth of a carburized layer of austenitic stainless steel according to claim 1, wherein: the austenitic stainless steel has a low pressureThe vacuum carburization treatment is carried out by feeding high-purity C into a vacuum furnace 2 H 2 Carburizing is performed.
3. The method for improving the corrosion resistance and the depth of a carburized layer of austenitic stainless steel according to claim 1, characterized in that: the pressure in the vacuum furnace in the carburizing period is controlled to be 50-150 Pa, and the pressure in the vacuum furnace in the diffusion period is controlled to be 150-350 Pa.
4. The method for improving the corrosion resistance and the depth of a carburized layer of austenitic stainless steel according to claim 1, wherein: and the heat treatment of the carburized austenitic stainless steel is carried out in a tubular furnace.
5. The method for improving the corrosion resistance and the depth of a carburized layer of austenitic stainless steel according to claim 1, wherein: the austenitic stainless steel pretreatment is to grind and polish the surface of the austenitic stainless steel and then carry out ultrasonic cleaning and drying.
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Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01230722A (en) * | 1988-03-08 | 1989-09-14 | Nisshin Steel Co Ltd | Manufacture of stainless steel material for cutting tool |
| JPH0971855A (en) * | 1995-06-27 | 1997-03-18 | Daido Hoxan Inc | Carbohardened table ware and production thereof |
| CN1423709A (en) * | 2000-01-28 | 2003-06-11 | 斯瓦戈洛克公司 | Modified low temperature case hardening processes |
| CN102828145A (en) * | 2012-08-09 | 2012-12-19 | 武汉材料保护研究所 | Low temperature gas carburizing method for realizing reinforcement and corrosion resistance of austenitic stainless steel |
| CN103305787A (en) * | 2013-06-25 | 2013-09-18 | 北京科技大学 | Method for preparing permeable layer blocking nitrogen and isotope thereof on stainless steel matrix |
| CN103398212A (en) * | 2013-08-12 | 2013-11-20 | 扬州科创表面硬化技术有限公司 | Valve rod |
| CN105714236A (en) * | 2014-12-05 | 2016-06-29 | 四川凌峰航空液压机械有限公司 | Vacuum pulse carburizing method for martensitic stainless steel |
| CN106835005A (en) * | 2016-12-21 | 2017-06-13 | 机械科学研究总院青岛分院 | A kind of cryogenic gas method for carburizing of austenitic stainless steel |
| CN107740032A (en) * | 2017-09-22 | 2018-02-27 | 成都万可瑞特金属科技有限公司 | The super shallow carburization heat treatment method of vacuum low-pressure |
| CN109735794A (en) * | 2019-03-08 | 2019-05-10 | 东北大学 | A kind of high-temperature carburizing stainless steel low-pressure vacuum carburization heat treatment method |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DK1910584T3 (en) * | 2005-06-22 | 2016-04-18 | Bodycote Plc | CARBONIZATION IN CARBON HYDRAD gas |
| US8696830B2 (en) * | 2010-07-21 | 2014-04-15 | Kenneth H. Moyer | Stainless steel carburization process |
| US8308873B2 (en) * | 2011-04-11 | 2012-11-13 | United Technologies Corporation | Method of processing steel and steel article |
-
2021
- 2021-12-10 CN CN202111507241.1A patent/CN114318210B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01230722A (en) * | 1988-03-08 | 1989-09-14 | Nisshin Steel Co Ltd | Manufacture of stainless steel material for cutting tool |
| JPH0971855A (en) * | 1995-06-27 | 1997-03-18 | Daido Hoxan Inc | Carbohardened table ware and production thereof |
| CN1423709A (en) * | 2000-01-28 | 2003-06-11 | 斯瓦戈洛克公司 | Modified low temperature case hardening processes |
| CN102828145A (en) * | 2012-08-09 | 2012-12-19 | 武汉材料保护研究所 | Low temperature gas carburizing method for realizing reinforcement and corrosion resistance of austenitic stainless steel |
| CN103305787A (en) * | 2013-06-25 | 2013-09-18 | 北京科技大学 | Method for preparing permeable layer blocking nitrogen and isotope thereof on stainless steel matrix |
| CN103398212A (en) * | 2013-08-12 | 2013-11-20 | 扬州科创表面硬化技术有限公司 | Valve rod |
| CN105714236A (en) * | 2014-12-05 | 2016-06-29 | 四川凌峰航空液压机械有限公司 | Vacuum pulse carburizing method for martensitic stainless steel |
| CN106835005A (en) * | 2016-12-21 | 2017-06-13 | 机械科学研究总院青岛分院 | A kind of cryogenic gas method for carburizing of austenitic stainless steel |
| CN107740032A (en) * | 2017-09-22 | 2018-02-27 | 成都万可瑞特金属科技有限公司 | The super shallow carburization heat treatment method of vacuum low-pressure |
| CN109735794A (en) * | 2019-03-08 | 2019-05-10 | 东北大学 | A kind of high-temperature carburizing stainless steel low-pressure vacuum carburization heat treatment method |
Non-Patent Citations (3)
| Title |
|---|
| Carbide precipitation in austenitic stainless steel carburized at low temperature;F. Ernst et al.;《Acta Materialia》;20071231;第55卷;第2部分 Experimental methods and procedures 第1段 * |
| Carbon Diffusion in 304l Austenitic Stainless Steel at 650-750℃ in Carburizing Environment;F.I.Haider et al.;《International Journal of Recent Technology and Engineering》;20190331;第7卷(第6S期);第76页右栏第2段，第77页左栏倒数第2段 * |
| High-temperature phase transformation in AISI 316 stainless steel infused with concentrated interstitial carbon;Zhe Ren et al.;《Journal of Alloys and Compounds》;20191121;第819卷;第11页第5部分 * |
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