CN111751511A - Method for detecting non-metallic inclusions in steel - Google Patents
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Abstract
The invention discloses a method for detecting nonmetallic inclusions in steel, which comprises the following steps: s1, sampling from a cast ingot or a cast blank of steel to be detected and preparing a tensile sample, heating and insulating the tensile sample to ensure that the tensile sample is carbonized and dissolved, then quickly cooling, and cleaning the surface to obtain the tensile sample to be detected; s2, performing tensile damage on the tensile sample to be tested; and S3, observing the appearance of the nonmetallic inclusion in the tensile fracture by adopting SEM, measuring the size of the nonmetallic inclusion and counting, detecting the components of the nonmetallic inclusion by adopting EDS, and analyzing the components of the inclusions in all size sections according to the EDS result to realize the detection of the nonmetallic inclusion in the steel. The detection method is simple and convenient, does not damage the appearance of the nonmetallic inclusion in the steel, and is favorable for researching the quality of the nonmetallic inclusion in the steel on steel products.
Description
Technical Field
The invention relates to the technical field of smelting, in particular to a method for detecting nonmetallic inclusions in steel.
Background
Non-inclusion is taken as an important factor influencing the quality of steel products, and often has a profound influence on the product performance. The non-metallic inclusions are found in steel materials and considered harmful and should be reduced as much as possible until now, partial inclusions are utilized to improve and improve the quality of the steel materials, and the non-metallic inclusions are always important evaluation indexes of steel products and are also important points of research in the field of steel smelting. In order to research the characteristics of the nonmetallic inclusions, namely the distribution, morphology, components and the like of the inclusions, the characteristics are generally characterized in the following two ways at the present stage, firstly, mechanical grinding and polishing are adopted to enable the surface of steel to meet certain requirements, the influence of external factors on characterization results is reduced as much as possible, and then the quantity, the distribution and the components of the steel are determined through an optical microscope and a scanning electron microscope. Secondly, extracting the non-metallic inclusions in the steel, and then determining the components, the morphology and the quantity of the non-metallic inclusions by adopting a scanning electron microscope, an XRD (X-ray diffraction), a transmission electron microscope and the like. Both of the above approaches have their own limitations.
When the non-metallic inclusion in the steel is represented by adopting a method of mechanical grinding and polishing, an optical microscope and a scanning electron microscope, the morphological characteristics of the non-metallic inclusion are inevitably damaged or the characteristics of the non-metallic inclusion at the position cannot be relatively completely represented in the mechanical grinding and polishing process. In addition, in the grinding and polishing process, part of the nonmetallic inclusion can fall off or be broken, and the accuracy and the effectiveness of the characterization result are seriously influenced. Although the method for representing the quantity, the components and the morphology of the inclusions by extracting the inclusions can completely present the features of the morphology, the components and the quantity of the nonmetallic inclusions, the process of extracting the inclusions is relatively complex and time-consuming, different steel products need to correspond to specific extraction liquid or electrolyte, and the extraction process is sensitive to the temperature environment.
Disclosure of Invention
The invention aims to solve the problems in the prior art and provides a method for detecting nonmetallic inclusions in steel.
The technical scheme adopted by the invention is as follows:
a method for detecting nonmetallic inclusions in steel comprises the following steps:
s1, sampling from a cast ingot or a cast blank of steel to be detected and preparing a tensile sample, heating and insulating the tensile sample to dissolve carbide in the tensile sample, then rapidly cooling, and cleaning the surface to obtain the tensile sample to be detected;
s2, performing tensile damage on the sample to be tested to peel off the nonmetallic inclusion from the matrix, so that the nonmetallic inclusion is exposed at the fracture;
and S3, observing the appearance of the nonmetallic inclusion in the tensile fracture by adopting SEM, measuring the size of the nonmetallic inclusion and counting, detecting the components of the nonmetallic inclusion by adopting EDS, and analyzing the components of the inclusions in all size sections according to the EDS result to realize the detection of the nonmetallic inclusion in the steel.
Preferably, in S1, the heat preservation temperature is 1100-1200 ℃, and the heat preservation time is 1-1.5 h.
Preferably, the cooling means is water cooling.
Preferably, in S1, the diameter d is cut from a cast or cast ingot of the steel to be examined11-1.5 cm long1Heating and insulating a round bar sample of 5-10 cm to dissolve carbide in a tensile sample, rapidly cooling, and turning a diameter d at the central part of the round bar sample23-5 mm long2And cleaning the round bar which is 1-1.5 cm to obtain the tensile sample to be tested.
Preferably, in S3, the non-metallic inclusions are observed at random, and the number of observed inclusions is 150 or more.
Preferably, in S3, when the sizes of the nonmetallic inclusions are counted, the proportions of the inclusions with the sizes of less than 2 μm, 2-3 μm, 3-4 μm, 4-5 μm, 5-10 μm and more than 10 μm are counted respectively; and analyzing the composition of the inclusions in each size section according to the EDS result.
Preferably, in S3, when the morphology of the nonmetallic inclusions is observed, different fractures are observed, and the number of the inclusions detected by each fracture is more than or equal to 75.
The invention has the following beneficial effects:
in the method for detecting the non-metallic inclusions in the steel, the inclusion detection sample is taken from an ingot or a casting blank which is not subjected to hot processing, so that the original appearance of the inclusions can be kept, and the inclusions are better stripped from a matrix when the inclusion detection sample is processed into a tensile sample. However, a small amount of carbide is difficult to precipitate in the process of molten steel solidification, and the tensile sample is subjected to heat preservation in order to make the carbide dissolve in a matrix and eliminate the influence of the carbide in the steel on a detection result, so that the melting point of the nonmetallic inclusion is very high, and the influence cannot be caused by heating. The rapid cooling is to prevent re-precipitation of carbides that are solid-dissolved into the matrix. The tensile damage to the tensile sample is to separate the inclusions from the matrix, so that the observation is convenient, and the damage to the inclusions by the existing mechanical method is avoided, because the nonmetal and the inclusions in the steel are not damaged by an external mechanical tool in the tensile process, the original morphological characteristics of the nonmetal and the inclusions can be kept, and the relative position information between the nonmetal inclusions and the matrix can be kept when the tensile fracture is broken out, so that the detection method can more comprehensively understand the morphology and the distribution condition of the nonmetal inclusions in the steel, and is favorable for researching the influence of the nonmetal inclusions on the performance of the steel; meanwhile, the invention exposes non-metal and sundries in the steel for detection in a stretching mode, thereby saving time and labor compared with an electrolytic method and having lower dependence degree on samples and environment. The appearance of the nonmetallic inclusion in the tensile fracture can be directly observed by adopting the SEM, the size of the inclusion can be directly measured, the corresponding inclusion components can be analyzed by the EDS, the inclusion components in all size sections can be counted, and further the comprehensive detection of the nonmetallic inclusion in the steel can be realized.
Furthermore, the temperature is kept at 1100-1200 ℃ for 1-1.5 h, and most of carbides in the steel can be ensured to be dissolved in the solution under the parameter, so that the influence of undissolved carbides on the detection result is avoided.
Furthermore, the tensile sample after heat preservation is cooled by adopting a water cooling mode, so that the re-precipitation of carbide dissolved in steel can be avoided, and meanwhile, the water cooling cannot pollute the sample and cannot cause cracks to the tensile sample easily.
Furthermore, the tensile sample adopts a rod-shaped sample, the sample is beneficial to holding during the tensile sample, the sample structure with a thin middle part and two thick ends is beneficial to controlling the fracture part, and the fracture part of the sample is generated in the thinner middle section.
Further, the inclusions in the steel are randomly analyzed, the number of the analyzed inclusions is more than or equal to 150, and the purpose is to comprehensively analyze the appearance and the components of the inclusions in the steel.
Furthermore, when the size of the nonmetallic inclusion is counted, the components of the inclusion in each size section are analyzed to obtain the inclusion counting information.
Furthermore, in order to integrally grasp inclusions in steel, one sample can be broken into two fractures, when the appearance of the nonmetallic inclusions is observed, different fractures are observed, the detection and analysis results are more accurate respectively, and meanwhile, the number of the inclusions detected by each fracture is more than or equal to 75 so as to obtain inclusion statistical information.
Drawings
FIG. 1 is a schematic flow chart showing a method for detecting nonmetallic inclusions in steel according to the present invention.
FIG. 2 is a flow chart of an embodiment of the present invention.
FIG. 3(a) is an SEM photograph of tensile fractures of example 1 of the present invention; FIG. 3(b) is an EDS diagram of inclusion No. 1 in FIG. 3 (a); FIG. 3(c) is an EDS chart of inclusion No. 2 in FIG. 3 (a); FIG. 3(d) is an EDS chart of inclusion No. 3 in FIG. 3 (a).
FIG. 4(a) is an SEM photograph of tensile fractures of example 2 of the present invention; FIG. 4(b) is an EDS diagram of inclusion No. 1 in FIG. 4 (a); FIG. 4(c) is an EDS chart of inclusion No. 2 in FIG. 4 (a); FIG. 4(d) is an EDS chart of inclusion No. 3 in FIG. 4 (a).
FIG. 5(a) is an SEM photograph of tensile fractures of example 3 of the present invention; FIG. 5(b) is an EDS diagram of inclusion No. 1 in FIG. 5 (a); FIG. 5(c) is an EDS chart of inclusion No. 2 in FIG. 5 (a); FIG. 5(d) is an EDS chart of inclusion No. 3 in FIG. 5 (a).
Detailed Description
The invention is further described with reference to the following figures and examples
Referring to fig. 1 and 2, the method for detecting nonmetallic inclusions in steel according to the present invention comprises the steps of:
(1) pretreatment of test samples
Selecting sample from ingot or casting blank to be detected, and threadingCutting into ingots or billets to obtain a diameter d11-1.5 cm long1A round bar sample of 5-10 cm; placing a round bar sample at 1100-1200 ℃ and preserving heat for 1-1.5 h, then cooling by water, and drying the sample as soon as possible after cooling; turning the middle part of the cooled sample to obtain a diameter d by adopting a lathe2L is 3-5 mm long2Cleaning a round bar sample of 1-1.5 cm for later use, wherein the cleaning of the round bar sample comprises removing an oxide layer and impurities on the surface and cleaning with alcohol.
(2) Stripping of non-metallic inclusions from the matrix
And (3) performing tensile damage on the pretreated round bar sample to peel the inclusions from the matrix, so that the inclusions are exposed.
(3) Detection of non-metallic inclusion morphology and composition
The sample is processed into a size capable of being placed in an SEM (scanning electron microscope), and before processing, a fracture needs to be protected by a raw material belt so as to prevent the fracture from being polluted in the processing process. And observing the appearance of the nonmetallic inclusions in the fracture of the round bar sample by adopting the SEM to ensure the detection accuracy, wherein the number of the inclusions detected in each fracture is more than or equal to 75. And measuring the size of the nonmetallic inclusion, and detecting the components of the nonmetallic inclusion by adopting EDS. And the appearance and the component of the nonmetallic inclusion are detected and observed to be two fractures. Selecting non-metallic inclusions randomly, observing the number of the non-metallic inclusions more than or equal to 150, and recording detection data (size, shape, components and the like) in an Excel document;
(4) inclusion statistical data processing
Counting the nonmetallic inclusions observed by the SEM, and respectively counting the proportions of the nonmetallic inclusions with the sizes of less than 2 microns, 2-3 microns, 3-4 microns, 4-5 microns, 5-10 microns and more than 10 microns; and analyzing the components of the nonmetallic inclusions in each size section according to the EDS result, and realizing the detection of the nonmetallic inclusions in the steel.
Example 1
The steel detected by the embodiment is CLAM steel, and the method for detecting the nonmetallic inclusions in the steel comprises the following steps:
(1) pretreatment of test samples
The sample is selected from steelCutting the cast ingot of CLAM steel into a diameter d by linear cutting1Length 1cm ═ 1cm1A 10cm round bar sample; placing a round bar sample at 1100 ℃ and keeping the temperature for 1.5h, then carrying out water cooling, and drying the sample as soon as possible after cooling; turning the middle part of the cooled sample to obtain a diameter d by adopting a lathe2Length l of 5mm2The round bar sample was cleaned for use after being set at 5 cm.
(2) Stripping of non-metallic inclusions from the matrix
And (3) performing tensile damage on the pretreated round bar sample to peel the inclusions from the matrix, so that the inclusions are exposed.
(3) Detection of non-metallic inclusion morphology and composition
The sample is processed into a size capable of being placed in an SEM (scanning electron microscope), and before processing, a fracture needs to be protected by a raw material belt so as to prevent the fracture from being polluted in the processing process. And (3) observing the appearance of the nonmetallic inclusions in the fracture of the round bar sample by adopting the SEM, wherein the number of the inclusions detected in the fracture is 75. And measuring the size of the nonmetallic inclusion, and detecting the components of the nonmetallic inclusion by adopting EDS. And the appearance and the component of the nonmetallic inclusion are detected and observed to be two fractures. Selecting non-metallic inclusions randomly, observing the number of the non-metallic inclusions to be 150, and recording detection data (size, shape, components and the like) in an Excel document;
SEM of the fracture in this example As shown in FIG. 3(a), a large number of inclusions were present in the fracture, and the inclusion composition was analyzed by EDS. The size of No. 1 inclusion was 3 μm, and as shown in FIG. 3(b), the composition was Fe-Cr-Ta-Mn-Y-O-S; the size of inclusion No. 2 was 1.1 μm, the composition was Fe-Cr-Y-O as shown in FIG. 3(c), the size of inclusion No. 3 was 0.4 μm, and the composition was Fe-Cr-Y-O as shown in FIG. 3 (d).
(4) Inclusion statistical data processing
Counting the nonmetallic inclusions observed by the SEM, and respectively counting the proportions of the nonmetallic inclusions with the sizes of less than 2 microns, 2-3 microns, 3-4 microns, 4-5 microns, 5-10 microns and more than 10 microns; and analyzing the components of the nonmetallic inclusions in each size section according to the EDS result, and realizing the detection of the nonmetallic inclusions in the steel.
TABLE 1
As shown in Table 1, the inclusion contents of inclusions having sizes of 2 μm or less, 2 to 3 μm, 3 to 4 μm, 4 to 5 μm, 5 to 10 μm and > 10 μm were 20.41%, 32.53%, 29.70%, 9.58%, 3.66% and 0.12%, respectively; the components are respectively Fe-Cr-Y-O, Fe-Cr-Y-O and MnS, Fe-Cr-Ta-Mn-Y-O-S and Fe-Cr-Y-O, Fe-Cr-Ta-Mn-Y-O-S, Fe-Cr-Ta-Mn-Y-O-S and Fe-Cr-Ta-Mn-Y-O-S.
Example 2
The steel detected by the embodiment is SCRAM, and the method for detecting the nonmetallic inclusions in the steel comprises the following steps:
(1) pretreatment of test samples
The sample is selected from the SCRAM steel ingot, and the diameter d is cut on the casting blank by linear cutting1Length of 1.5cm1Round bar sample of 5 cm; placing a round bar sample at 1200 ℃ and keeping the temperature for 1.5h, then carrying out water cooling, and drying the sample as soon as possible after cooling; turning the middle part of the cooled sample to obtain a diameter d by adopting a lathe2Length l 3mm2The round bar sample was cleaned and used as 1.
(2) Stripping of non-metallic inclusions from the matrix
And (3) performing tensile damage on the pretreated round bar sample to peel the inclusions from the matrix, so that the inclusions are exposed.
(3) Detection of non-metallic inclusion morphology and composition
The sample is processed into a size capable of being placed in an SEM (scanning electron microscope), and before processing, a fracture needs to be protected by a raw material belt so as to prevent the fracture from being polluted in the processing process. And (3) observing the appearance of the nonmetallic inclusions in the fracture of the round bar sample by adopting the SEM, wherein the number of the inclusions detected in the fracture is 85. And measuring the size of the nonmetallic inclusion, and detecting the components of the nonmetallic inclusion by adopting EDS. And the appearance and the component of the nonmetallic inclusion are detected and observed to be two fractures. Selecting non-metallic inclusions randomly, observing the number of the non-metallic inclusions to be 170, and recording detection data (size, shape, components and the like) in an Excel document;
SEM of the fracture in this example As shown in FIG. 4(a), a large number of inclusions were present in the fracture, and the inclusion composition was analyzed by EDS. The size of No. 1 inclusion was 4.5 μm, and as shown in FIG. 4(b), the composition was Fe-Cr-Mn-Ti-V-O; the size of the No. 2 inclusion was 1.8 μm, as shown in FIG. 4(c), the composition was Fe-Cr-Mn-Ti-V-O-S, and the size of the No. 3 inclusion was 2.4 μm, as shown in FIG. 4(d), the composition was Fe-Cr-Ti-Y-O.
(4) Inclusion statistical data processing
Counting the nonmetallic inclusions observed by the SEM, and respectively counting the proportions of the nonmetallic inclusions with the sizes of less than 2 microns, 2-3 microns, 3-4 microns, 4-5 microns, 5-10 microns and more than 10 microns; and analyzing the components of the nonmetallic inclusions in each size section according to the EDS result, and realizing the detection of the nonmetallic inclusions in the steel.
TABLE 2
| |
2 μm or less | 2～ |
3～4μm | 4～ |
5～10μm | ＞10μm |
| Ratio/%) | 31.2 | 23.1 | 26.4 | 16.4 | 2.7 | 0.2 |
| Composition (I) | Fe-Cr-Mn-Ti-V-O-S | Fe-Cr-Ti-Y-O | Fe-Cr-Ti-Y-O | Fe-Cr-Mn-Ti-V-O | Fe-Cr-Ti-V-O | Fe-Cr-Ti-V-O |
As shown in Table 2, the inclusion contents of inclusions having sizes of 2 μm or less, 2 to 3 μm, 3 to 4 μm, 4 to 5 μm, 5 to 10 μm and > 10 μm were 31.2%, 23.1%, 26.4%, 16.4%, 2.7% and 0.2%, respectively; the components are Fe-Cr-Mn-Ti-V-O-S, Fe-Cr-Ti-Y-O, Fe-Cr-Ti-Y-O, Fe-Cr-Mn-Ti-V-O, Fe-Cr-Ti-V-O and Fe-Cr-Ti-V-O respectively.
Example 3
The steel detected by the embodiment is ARAA steel, and the method for detecting the nonmetallic inclusions in the steel comprises the following steps:
(1) pretreatment of test samples
The sample is selected from ARAA ingot made of steel, and the diameter d is cut on the casting blank by linear cutting1Length l of 1.25cm1Round bar sample of 7.5 cm; placing a round bar sample at 1150 ℃ for heat preservation for 1.25h, cooling by water, and drying the sample as soon as possible after cooling; turning the middle part of the cooled sample to obtain a diameter d by adopting a lathe2Length l 4.5mm2The round bar sample was cleaned and ready for use as 1.25 round bar sample.
(2) Stripping of non-metallic inclusions from the matrix
And (3) performing tensile damage on the pretreated round bar sample to peel the inclusions from the matrix, so that the inclusions are exposed.
(3) Detection of non-metallic inclusion morphology and composition
The sample is processed into a size capable of being placed in an SEM (scanning electron microscope), and before processing, a fracture needs to be protected by a raw material belt so as to prevent the fracture from being polluted in the processing process. And (3) observing the appearance of the nonmetallic inclusions in the fracture of the round bar sample by adopting the SEM, wherein the number of the inclusions detected in the fracture is 86. And measuring the size of the nonmetallic inclusion, and detecting the components of the nonmetallic inclusion by adopting EDS. And the appearance and the component of the nonmetallic inclusion are detected and observed to be two fractures. Selecting nonmetallic inclusions as random selection, observing the nonmetallic inclusions with the number of 172, and recording detection data (size, shape, components and the like) in an Excel document;
SEM of the fracture in this example As shown in FIG. 5(a), a large number of inclusions were present in the fracture, and the inclusion composition was analyzed by EDS. The size of No. 1 inclusion was 1.9 μm, and as shown in FIG. 5(b), the composition was Fe-Cr-Y-Zr-O; the size of inclusion No. 2 was 2.4 μm, as shown in FIG. 5(c), and the composition was Fe-Cr-Mn-Ti-V-Zr-O, and the size of inclusion No. 3 was 4.2 μm, as shown in FIG. 5(d), and the composition was Fe-Cr-Mn-W-Ti-Zr-V-O.
(4) Inclusion statistical data processing
Counting the nonmetallic inclusions observed by the SEM, and respectively counting the proportions of the nonmetallic inclusions with the sizes of less than 2 microns, 2-3 microns, 3-4 microns, 4-5 microns, 5-10 microns and more than 10 microns; and analyzing the components of the nonmetallic inclusions in each size section according to the EDS result, and realizing the detection of the nonmetallic inclusions in the steel.
TABLE 3
| |
2 μm or less | 2～ |
3～4μm | 4～ |
5～10μm | ＞10μm |
| Ratio/%) | 17.2 | 18.4 | 30.5 | 18.1 | 13.6 | 2.2 |
| Composition (I) | Fe-Cr-Y-Zr-O | Fe-Cr-Mn-Ti-V-Zr-O | Fe-Cr-Mn-Ti-V-Zr-O | Fe-Cr-Mn-W-Ti-Zr-V-O | Fe-Cr-Mn-W-Ti-Zr-V-O | Fe-Cr-W-Ti-Zr-V-O |
As shown in Table 3, the inclusion contents of inclusions having sizes of 2 μm or less, 2 to 3 μm, 3 to 4 μm, 4 to 5 μm, 5 to 10 μm and > 10 μm were 17.2%, 18.4%, 30.5%, 18.1%, 13.6% and 2.2%, respectively; the components are Fe-Cr-Y-Zr-O, Fe-Cr-Mn-Ti-V-Zr-O, Fe-Cr-Mn-Ti-V-Zr-O, Fe-Cr-Mn-W-Ti-Zr-V-O, Fe-Cr-Mn-W-Ti-Zr-V-O and Fe-Cr-W-Ti-Zr-V-O respectively.
Claims (7)
1. A method for detecting nonmetallic inclusions in steel is characterized by comprising the following steps:
s1, sampling from a cast ingot or a cast blank of steel to be detected and preparing a tensile sample, heating and insulating the tensile sample to dissolve carbide in the tensile sample, then rapidly cooling, and cleaning the surface to obtain the tensile sample to be detected;
s2, performing tensile damage on the tensile sample to be tested;
and S3, observing the appearance of the nonmetallic inclusion in the tensile fracture by adopting SEM, measuring the size of the nonmetallic inclusion and counting, detecting the components of the nonmetallic inclusion by adopting EDS, and analyzing the components of the inclusions in all size sections according to the EDS result to realize the detection of the nonmetallic inclusion in the steel.
2. The method for detecting nonmetallic inclusions in steel as claimed in claim 1, wherein the heat-preserving temperature in S1 is 1100-1200 ℃ and the heat-preserving time is 1-1.5 h.
3. The method for detecting nonmetallic inclusions in steel as claimed in claim 2, wherein the cooling means is water cooling.
4. The method for detecting nonmetallic inclusions in steel as claimed in claim 2, wherein in S1, the diameter d is cut from an ingot or billet of steel to be detected11-1.5 cm long1Heating and insulating a round bar sample of 5-10 cm to dissolve carbide in a tensile sample, rapidly cooling, and turning a diameter d at the central part of the round bar sample23-5 mm long2And cleaning the round bar which is 1-1.5 cm to obtain the tensile sample to be tested.
5. The method of claim 1, wherein in S3, the number of non-metallic inclusions observed is 150 or more, and the number of non-metallic inclusions observed is randomly selected when observing the non-metallic inclusions.
6. The method of claim 5, wherein in S3, when the sizes of the non-metallic inclusions are counted, the proportions of inclusions with sizes below 2 μm, 2-3 μm, 3-4 μm, 4-5 μm, 5-10 μm and > 10 μm are counted; and analyzing the composition of the inclusions in each size section according to the EDS result.
7. The method for detecting nonmetallic inclusions in steel according to claim 1, wherein in S3, when morphology of nonmetallic inclusions is observed, different fractures are observed, and the number of detected inclusions in each fracture is more than or equal to 75.
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| CN202010605893.8A CN111751511A (en) | 2020-06-29 | 2020-06-29 | Method for detecting non-metallic inclusions in steel |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112924470A (en) * | 2021-02-02 | 2021-06-08 | 燕山大学 | Method for rapidly detecting non-metallic inclusions in steel |
| CN113484373A (en) * | 2021-07-02 | 2021-10-08 | 西安建筑科技大学 | Semi-coke quality control method based on resistivity detection and application thereof |
| CN115267119A (en) * | 2022-07-18 | 2022-11-01 | 中天钢铁集团有限公司 | Method for detecting large-size nonmetallic inclusion |
| CN115639235A (en) * | 2022-09-28 | 2023-01-24 | 南京钢铁股份有限公司 | Spring steel rolled material purity characterization method |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109596658A (en) * | 2018-12-31 | 2019-04-09 | 盛利维尔（中国）新材料技术股份有限公司 | A method of being mingled with detection for high-strength steel bulky grain |
| WO2019117552A1 (en) * | 2017-12-11 | 2019-06-20 | 주식회사 포스코 | Steel manufacturing method and steel |
| CN110006751A (en) * | 2019-04-10 | 2019-07-12 | 北京交通大学 | The appraisal procedure of high-intensitive nonmetallic inclusionsin steel |
-
2020
- 2020-06-29 CN CN202010605893.8A patent/CN111751511A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2019117552A1 (en) * | 2017-12-11 | 2019-06-20 | 주식회사 포스코 | Steel manufacturing method and steel |
| CN109596658A (en) * | 2018-12-31 | 2019-04-09 | 盛利维尔（中国）新材料技术股份有限公司 | A method of being mingled with detection for high-strength steel bulky grain |
| CN110006751A (en) * | 2019-04-10 | 2019-07-12 | 北京交通大学 | The appraisal procedure of high-intensitive nonmetallic inclusionsin steel |
Non-Patent Citations (6)
| Title |
|---|
| 刘剑辉等: "超低氧弹簧钢60Si2MnA疲劳断口夹杂物来源研究", 《中国冶金》 * |
| 包卫平等: "不同热处理工艺对Fe-30Mn-3Si-4Al TWIP钢力学组织性能的影响", 《精密成形工程》 * |
| 吴润 等: "《钢铁质量及其构件失效分析》", 30 April 2018 * |
| 薛小怀, 上海交通大学出版社 * |
| 赵海民等: "2000 MPa高强度钢的超高周疲劳破坏行为", 《特殊钢》 * |
| 陈然等: "轴承钢夹杂物行为的原位观察", 《钢铁研究学报》 * |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112924470A (en) * | 2021-02-02 | 2021-06-08 | 燕山大学 | Method for rapidly detecting non-metallic inclusions in steel |
| CN113484373A (en) * | 2021-07-02 | 2021-10-08 | 西安建筑科技大学 | Semi-coke quality control method based on resistivity detection and application thereof |
| CN113484373B (en) * | 2021-07-02 | 2024-01-19 | 西安建筑科技大学 | Semi-coke quality control method based on resistivity detection and application thereof |
| CN115267119A (en) * | 2022-07-18 | 2022-11-01 | 中天钢铁集团有限公司 | Method for detecting large-size nonmetallic inclusion |
| CN115639235A (en) * | 2022-09-28 | 2023-01-24 | 南京钢铁股份有限公司 | Spring steel rolled material purity characterization method |
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