CN113740131A - Crystal boundary display method of bainite steel - Google Patents
Crystal boundary display method of bainite steel Download PDFInfo
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- CN113740131A CN113740131A CN202111042026.9A CN202111042026A CN113740131A CN 113740131 A CN113740131 A CN 113740131A CN 202111042026 A CN202111042026 A CN 202111042026A CN 113740131 A CN113740131 A CN 113740131A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
- G01N1/286—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q involving mechanical work, e.g. chopping, disintegrating, compacting, homogenising
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D6/00—Heat treatment of ferrous alloys
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- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
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- G01N1/32—Polishing; Etching
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Abstract
The invention provides a grain boundary display method of bainite steel, which comprises the following steps: A) carrying out heat treatment on the bainite steel sample, wherein the temperature of the heat treatment is 350-400 ℃, the heat preservation time is 0.5-1.5 h, and then cooling; B) grinding and polishing the sample obtained in the step A) to obtain a metallographic sample, and corroding the metallographic sample by adopting a saturated picric acid aqueous solution; C) and acquiring the grain boundary information of the corroded metallographic specimen through image acquisition software. According to the method, the saturated picric acid aqueous solution is used for corroding the bainite steel tempered at the medium temperature, so that actual crystal grains and crystal boundaries of the sample can be clearly displayed.
Description
Technical Field
The invention relates to the technical field of physical inspection of metal materials, in particular to a crystal boundary display method of a bainite steel rail.
Background
Along with the development of railways towards high speed and heavy load, higher requirements are put forward on the performance of the steel rail, and the pearlite steel rail is difficult to further improve the strength and the wear resistance under the existing technical conditions. The bainite steel rail has the characteristics of good toughness, high fatigue strength, good wear resistance and the like, and is gradually the key point of research in research institutions and steel rail production enterprises.
The bainite steel rail is mainly bainite/martensite complex phase steel, carbide-free bainite steel and the like, cementite in a bainite structure is likely to become a crack initiation source, the precipitation of carbide needs to be inhibited through an alloy element Si, and the cementite is replaced by residual austenite rich in carbon in the structure transformation process to form a special bainite steel rail structure. The research of no-carbide bainite steel rail by Jinjiong et al shows that the microstructure mainly comprises M-A islands, lath bainite ferrite, residual austenite and a very small amount of ferrite with different scales by tempering at 350 ℃, the bainite in the microstructure is obviously precipitated at 450 ℃, and the residual austenite is decomposed along with the rise of the tempering temperature to generate adverse effect on the mechanical property of the material, so that the stability of the structure and the performance is ensured by adopting low-temperature tempering in the industry at present, the carbide can be precipitated on the austenite crystal boundary by reasonably adopting medium-temperature tempering, and the bainite crystal boundary can be clearly displayed by adopting a specific corrosion method.
The current display of austenite grain boundaries includes a carburizing method, a simulated carburizing method, a ferrite network method, an oxidation method, a direct hardening method, a cementite network method and a fine pearlite network method, wherein the cementite network method is mainly used for forming carbides and displaying the grain boundaries without adding atmosphere, but the method heats a sample to about an austenitizing temperature of 820 ℃, keeps the temperature for 30min, and cools the sample to be below a lower critical temperature at a slow cooling speed to precipitate the carbides from the austenite grain boundaries, and the method needs to measure the critical temperature of steel. Fine pearlite steel rail austenite grain size is usually a fine pearlite net method and a direct hardening method, wherein the fine pearlite net method is mainly a method aiming at eutectoid steel, and a sample is incompletely hardened or a gradient hardening method is adopted, so that austenite grains are surrounded by fine pearlite; the direct hardening method needs to heat the sample to the complete austenitizing temperature, keep the temperature for 1h, quench at a higher cooling speed to obtain the martensite structure, temper for 15min at about 230 ℃ before corrosion to improve the contrast, finally prepare the sample obtained by heat treatment into a metallographic sample, and display the grain boundary by adopting active agents such as picric acid aqueous solution, detergent and the like according to a certain concentration ratio and corrosion at a certain temperature.
Disclosure of Invention
The invention aims to provide a method for displaying the grain boundary of bainite steel, which can clearly display the bainite grain boundary.
In view of the above, the present application provides a grain boundary display method for bainite steel, including the steps of:
A) carrying out heat treatment on the bainite steel sample, wherein the temperature of the heat treatment is 350-400 ℃, the heat preservation time is 0.5-1.5 h, and then cooling;
B) grinding and polishing the sample obtained in the step A) to obtain a metallographic sample, and corroding the metallographic sample by adopting a saturated picric acid aqueous solution;
C) and acquiring the grain boundary information of the corroded metallographic specimen through image acquisition software.
Preferably, the temperature of the heat treatment is 360-390 ℃, and the heat preservation time is 0.8-1.2 h.
Preferably, the temperature of the saturated picric acid aqueous solution is 30-70 ℃.
Preferably, the corrosion time is 5-20 s.
Preferably, the corrosion process is specifically as follows:
and wiping the metallographic specimen with absorbent cotton until the surface is light gray, wiping with soapy water, and finally washing with running water and blow-drying.
Preferably, the histogram mode of the image acquisition software is a Spline mode or Best Fit.
The application provides a crystal boundary display method for bainite steel, which adopts medium-temperature tempering at 350-400 ℃ to decompose residual austenite to form along-crystal cementite, wherein a formed cementite network is actual crystal grains of the bainite steel, and the saturated picric acid aqueous solution is used for corroding the bainite steel subjected to medium-temperature tempering, so that the actual crystal grains and the crystal boundary of a sample can be clearly displayed.
Drawings
FIG. 1 is a metallographic photograph of a sample of a bainitic rail prepared in example 1 of the present invention;
FIG. 2 is a metallographic photograph of a sample of bainite rail prepared in example 2 of the present invention.
Detailed Description
For a further understanding of the invention, reference will now be made to the preferred embodiments of the invention by way of example, and it is to be understood that the description is intended to further illustrate features and advantages of the invention, and not to limit the scope of the claims.
The Pan steel utilizes the effect that silicon has strong resistance to carbide precipitation, and the original carbide precipitation part in the bainite steel exists in the form of residual austenite, so that a series of quasi-bainite steels are successfully developed. The bainite steel has a typical structure of bainite ferrite and residual austenite, and the residual austenite is distributed among laths of the bainite ferrite and in a discontinuous film shape; with conventional etching methods, it is difficult to show grain boundaries of carbide bainite and bainite steel bainite. Therefore, the application provides a method for displaying the grain boundary of bainite steel, in particular to a method for displaying the grain boundary of a bainite steel rail, wherein the difficulty of displaying the grain boundary of the bainite steel rail is that the actual grain boundary of bainite does not move; and the conventional bainite steel rail is heated to austenitize, quickly cooled to form martensite, and after low-temperature tempering, the structure is tested to be the essential grain size of the bainite steel rail instead of the actual grain size by adopting the conventional metallographic grinding, polishing and corrosion methods. Specifically, the embodiment of the invention discloses a grain boundary display method of bainite steel, which comprises the following steps:
A) carrying out heat treatment on the bainite steel sample, wherein the temperature of the heat treatment is 350-400 ℃, the heat preservation time is 0.5-1.5 h, and then cooling;
B) grinding and polishing the sample obtained in the step A) to obtain a metallographic sample, and corroding the metallographic sample by adopting a saturated picric acid aqueous solution;
C) and acquiring the grain boundary information of the corroded metallographic specimen through image acquisition software.
In the application, a bainite steel sample is heated to 350-400 ℃ to be tempered at a medium temperature, unstable residual austenite on a grain boundary in a structure begins to be decomposed into carbide, and a formed cementite network is an actual crystal grain of a bainite steel rail. In the process, the heat preservation time is 0.5-1.5 h, and then the cooling is furnace cooling and is cooled to the room temperature.
According to a conventional mode in the field, the cooled sample is sequentially ground and polished to obtain a metallographic sample, and then the metallographic sample is corroded by a saturated picric acid aqueous solution, wherein the saturated picric acid aqueous solution has the effect of preferentially corroding a cementite grain boundary, and the grain boundary display is clearer by controlling the corrosion temperature to be 30-70 ℃ and the time to be 5-20 s and better increasing the structure contrast ratio of the grain boundary and a matrix. The specific corrosion process is as follows: and wiping the metallographic specimen with absorbent cotton until the surface is light gray, wiping with soapy water, and finally washing with running water and blow-drying.
In the method, the grain boundary information of the corroded metallographic specimen is finally obtained through image acquisition software, and in the process, a Spline mode and a Best Fit are selected in a histogram mode, so that the image quality reaches the Best state.
In order to further understand the present invention, the method for displaying grain boundaries of bainite steel provided by the present invention is described in detail below with reference to the following examples, and the scope of the present invention is not limited by the following examples.
The composition of the PB2 bainite rail in the following examples is shown in table 1;
TABLE 1 Bainite Steel Rail composition data sheet
| Name (R) | C | Si | Mn | P | S | Cr | Mo |
| PB2 | 0.23 | 1.58 | 1.97 | 0.010 | 0.006 | 0.80 | 0.30 |
Example 1
Cutting a sample to be measured of 10mm on a PB2 bainite steel rail produced by climbing steel, placing the sample in a heat treatment furnace, heating to 400 ℃, preserving heat for 1h, cooling the furnace to room temperature, grinding and polishing the heat-treated sample to prepare a metallographic sample, wiping the sample in a saturated picric acid aqueous solution at 50 ℃ by absorbent cotton until the surface is light gray, scrubbing by a soap aqueous solution, and finally washing and drying by flowing water; the grain boundary information was obtained by image acquisition software, as shown in fig. 1.
Example 2
Cutting a sample to be measured of 10mm on a PB2 bainite steel rail produced by climbing steel, placing the sample in a heat treatment furnace, heating to 380 ℃, preserving heat for 1h, cooling the furnace to room temperature, grinding and polishing the heat-treated sample to prepare a metallographic sample, wiping the sample in a saturated picric acid aqueous solution at 40 ℃ by absorbent cotton until the surface is light gray, scrubbing by a soap aqueous solution, and finally washing and drying by flowing water; the grain boundary information was obtained by image acquisition software, as shown in fig. 2.
After the method is used, a matrix is light brown, crystal boundaries are black, if the nitric acid alcohol solution is used, the matrix and the crystal boundaries are both black, the contrast is not obvious enough, if the picric acid corrosion inhibitor is used, the crystal boundaries are black, the matrix is not corroded, and the contrast is obvious, but the method has complex control on the dosage of the corrosion inhibitor and the corrosion temperature, and the method achieves relatively excellent corrosion effect by using the simplest corrosion method.
The above description of the embodiments is only intended to facilitate the understanding of the method of the invention and its core idea. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (6)
1. A grain boundary display method of bainite steel comprises the following steps:
A) carrying out heat treatment on the bainite steel sample, wherein the temperature of the heat treatment is 350-400 ℃, the heat preservation time is 0.5-1.5 h, and then cooling;
B) grinding and polishing the sample obtained in the step A) to obtain a metallographic sample, and corroding the metallographic sample by adopting a saturated picric acid aqueous solution;
C) and acquiring the grain boundary information of the corroded metallographic specimen through image acquisition software.
2. The grain boundary display method according to claim 1, wherein the heat treatment temperature is 360 to 390 ℃, and the heat preservation time is 0.8 to 1.2 hours.
3. The grain boundary display method according to claim 1, wherein the temperature of the saturated picric acid aqueous solution is 30 to 70 ℃.
4. The grain boundary display method according to claim 1, wherein the etching time is 5 to 20 seconds.
5. The grain boundary display method according to claim 1, wherein the etching process is specifically:
and wiping the metallographic specimen with absorbent cotton until the surface is light gray, wiping with soapy water, and finally washing with running water and blow-drying.
6. The grain boundary display method according to claim 5, wherein the histogram mode of the image acquisition software is Spline mode or Best Fit.
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Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102890027A (en) * | 2012-09-29 | 2013-01-23 | 攀钢集团攀枝花钢铁研究院有限公司 | Metallographic structure display method of interstitial free (IF) steel cold-rolled sheet containing titanium (Ti) |
| CN103175726A (en) * | 2013-03-12 | 2013-06-26 | 上海大学 | Metallographic corrosion method for clearly displaying original austenite grain boundary of NiCrMoV type rotor steel |
| CN103454187A (en) * | 2013-08-27 | 2013-12-18 | 宁夏共享集团有限责任公司 | Method for displaying original austenite grain boundary of tempering bainite structure at room temperature |
| CN103938149A (en) * | 2014-04-11 | 2014-07-23 | 人本集团有限公司 | Metallographic detection sample preparation method after carbonitriding of high-carbon chromium bearing steel, as well as product |
| CN104458511A (en) * | 2014-12-01 | 2015-03-25 | 上海交通大学 | Method for testing autstenitic grain size of steel bainite structure for nuclear pressure vessel |
| CN105547796A (en) * | 2015-12-21 | 2016-05-04 | 中车戚墅堰机车车辆工艺研究所有限公司 | A metallographic phase corrosive used for displaying a tempered sorbite tissue austenite crystal boundary and a corroding method |
| CN105628480A (en) * | 2015-12-21 | 2016-06-01 | 中车戚墅堰机车车辆工艺研究所有限公司 | Corrosive for displaying grain boundary of original austenite of tempered martensite and corroding method |
| CN105838861A (en) * | 2016-05-26 | 2016-08-10 | 中国科学院金属研究所 | Heat treatment method for maraging stainless steel |
| CN109238813A (en) * | 2018-09-19 | 2019-01-18 | 邢台钢铁有限责任公司 | The detection display methods of spring steel austenite grain |
| CN110132962A (en) * | 2019-04-24 | 2019-08-16 | 东方电气集团东方锅炉股份有限公司 | A kind of original austenite crystal prevention display methods of boiler and pressure vessel tempering bainite steel |
| CN110468416A (en) * | 2019-08-08 | 2019-11-19 | 重庆科技学院 | Show the corrosive liquid and preparation method and application of super-high strength steel austenite grain boundary and transgranular bainite and martensite |
| CN110926913A (en) * | 2019-12-31 | 2020-03-27 | 北京科技大学 | Display method of spring steel austenite grains |
-
2021
- 2021-09-07 CN CN202111042026.9A patent/CN113740131B/en active Active
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102890027A (en) * | 2012-09-29 | 2013-01-23 | 攀钢集团攀枝花钢铁研究院有限公司 | Metallographic structure display method of interstitial free (IF) steel cold-rolled sheet containing titanium (Ti) |
| CN103175726A (en) * | 2013-03-12 | 2013-06-26 | 上海大学 | Metallographic corrosion method for clearly displaying original austenite grain boundary of NiCrMoV type rotor steel |
| CN103454187A (en) * | 2013-08-27 | 2013-12-18 | 宁夏共享集团有限责任公司 | Method for displaying original austenite grain boundary of tempering bainite structure at room temperature |
| CN103938149A (en) * | 2014-04-11 | 2014-07-23 | 人本集团有限公司 | Metallographic detection sample preparation method after carbonitriding of high-carbon chromium bearing steel, as well as product |
| CN104458511A (en) * | 2014-12-01 | 2015-03-25 | 上海交通大学 | Method for testing autstenitic grain size of steel bainite structure for nuclear pressure vessel |
| CN105547796A (en) * | 2015-12-21 | 2016-05-04 | 中车戚墅堰机车车辆工艺研究所有限公司 | A metallographic phase corrosive used for displaying a tempered sorbite tissue austenite crystal boundary and a corroding method |
| CN105628480A (en) * | 2015-12-21 | 2016-06-01 | 中车戚墅堰机车车辆工艺研究所有限公司 | Corrosive for displaying grain boundary of original austenite of tempered martensite and corroding method |
| CN105838861A (en) * | 2016-05-26 | 2016-08-10 | 中国科学院金属研究所 | Heat treatment method for maraging stainless steel |
| CN109238813A (en) * | 2018-09-19 | 2019-01-18 | 邢台钢铁有限责任公司 | The detection display methods of spring steel austenite grain |
| CN110132962A (en) * | 2019-04-24 | 2019-08-16 | 东方电气集团东方锅炉股份有限公司 | A kind of original austenite crystal prevention display methods of boiler and pressure vessel tempering bainite steel |
| CN110468416A (en) * | 2019-08-08 | 2019-11-19 | 重庆科技学院 | Show the corrosive liquid and preparation method and application of super-high strength steel austenite grain boundary and transgranular bainite and martensite |
| CN110926913A (en) * | 2019-12-31 | 2020-03-27 | 北京科技大学 | Display method of spring steel austenite grains |
Non-Patent Citations (1)
| Title |
|---|
| 冯喜锋 等: "热轧板带轧辊彩色金相组织的检测及分析探讨", 《现代冶金》 * |
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