CN113466271B - Method for accurately determining type, morphology and elemental composition of intermetallic compounds in steel - Google Patents
Method for accurately determining type, morphology and elemental composition of intermetallic compounds in steel Download PDFInfo
- Publication number
- CN113466271B CN113466271B CN202110873213.5A CN202110873213A CN113466271B CN 113466271 B CN113466271 B CN 113466271B CN 202110873213 A CN202110873213 A CN 202110873213A CN 113466271 B CN113466271 B CN 113466271B
- Authority
- CN
- China
- Prior art keywords
- electrolysis
- precipitated phase
- sample
- beaker
- powder
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N23/00—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00
- G01N23/20—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by using diffraction of the radiation by the materials, e.g. for investigating crystal structure; by using scattering of the radiation by the materials, e.g. for investigating non-crystalline materials; by using reflection of the radiation by the materials
- G01N23/207—Diffractometry using detectors, e.g. using a probe in a central position and one or more displaceable detectors in circumferential positions
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N23/00—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00
- G01N23/20—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by using diffraction of the radiation by the materials, e.g. for investigating crystal structure; by using scattering of the radiation by the materials, e.g. for investigating non-crystalline materials; by using reflection of the radiation by the materials
- G01N23/20008—Constructional details of analysers, e.g. characterised by X-ray source, detector or optical system; Accessories therefor; Preparing specimens therefor
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N23/00—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00
- G01N23/22—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by measuring secondary emission from the material
- G01N23/2202—Preparing specimens therefor
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N23/00—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00
- G01N23/22—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by measuring secondary emission from the material
- G01N23/225—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by measuring secondary emission from the material using electron or ion
- G01N23/2251—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by measuring secondary emission from the material using electron or ion using incident electron beams, e.g. scanning electron microscopy [SEM]
Landscapes
- Chemical & Material Sciences (AREA)
- Biochemistry (AREA)
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Analytical Chemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Crystallography & Structural Chemistry (AREA)
- Analysing Materials By The Use Of Radiation (AREA)
- Investigating And Analyzing Materials By Characteristic Methods (AREA)
Abstract
The invention discloses a method for accurately determining the type, morphology and elemental composition of intermetallic compounds in steel, belongs to the technical field of metal material analysis, and solves the problems that the type of intermetallic compounds cannot be accurately determined and chemical components in the intermetallic compounds cannot be accurately determined when a massive sample is adopted for X-ray diffraction in the prior art. Comprises electrolyzing and extracting an electrolysis sample, dissolving a matrix, and enriching precipitated phase powder; analyzing the enriched precipitated phase powder by adopting X-ray diffraction to determine the type of the precipitated phase; dissolving the carbide by a phase separation method to realize the separation of the carbide from intermetallic compounds and free carbon; determining the type of the intermetallic compound by X-ray diffraction; separating free carbon in the intermetallic compound by adopting ultrasonic oscillation; and observing the appearance of the intermetallic compound by adopting a scanning electron microscope, and carrying out energy spectrum analysis on the intermetallic compound. The method can realize the accurate analysis of the components of the intermetallic compound.
Description
Technical Field
The invention belongs to the technical field of metal material analysis, and particularly relates to a method for accurately determining the type, morphology and elemental composition of intermetallic compounds in steel.
Background
X-ray diffraction allows phase analysis to determine the phase type. Because the content of precipitated phases in steel and alloy is low, if a massive sample is directly used for X-ray diffraction, only the diffraction spectrum peak of a matrix can be obtained, and the type of the precipitated phases cannot be accurately determined. The scanning electron microscope is a large-scale precise instrument for analyzing the high-resolution micro-area morphology, has the characteristics of large depth of field, high resolution, visual imaging, strong stereoscopic impression, wide magnification range and the like, and can simultaneously obtain information such as morphology, structure, components and the like. Generally, a sample preparation method for observing precipitated phases in steel or alloy by adopting a scanning electron microscope is an etching method, a proper corrosive agent is selected in the etching process to ensure that the precipitated phases do not fall off in the etching process, but for trace phases, the existence of the trace phases is difficult to determine due to the existence of other large quantities of phases. The corrosion is directly carried out by using a block sample, and for a small particle precipitated phase, when the content of elements in the precipitated phase is analyzed by adopting an energy spectrum, the interference of a matrix is easy to occur, and the chemical components in the small precipitated phase cannot be accurately measured. The precipitated phases in the steel often comprise chi-phase and mu-phase intermetallic compounds, and the chi-phase and mu-phase intermetallic compounds have no age hardening effect and can reduce the performance of the steel, so that the types, the appearances, the element contents and the like of the precipitated phases are accurately analyzed, a certain effect is realized on the aspects of designing alloy components, selecting a heat treatment system and the like, and the chi-phase and mu-phase intermetallic compounds are avoided as far as possible. Currently, there is little research on how to accurately determine intermetallic compound types, morphologies, and elemental compositions in steel.
Disclosure of Invention
In view of the above analysis, the present invention aims to provide a method for accurately determining the type, morphology and elemental composition of intermetallic compounds in steel, which can solve at least one of the following technical problems: (1) In the prior art, when a blocky sample is adopted for X-ray diffraction, the type of an intermetallic compound cannot be accurately determined; (2) A scanning electron microscope is directly used for detecting a blocky sample, and when the content of elements in the intermetallic compound is analyzed by adopting an energy spectrum, the blocky sample is easily interfered by a matrix, and the chemical components in the fine intermetallic compound cannot be accurately measured.
The invention is mainly realized by the following technical scheme:
the invention provides a method for accurately measuring the type, morphology and elemental composition of intermetallic compounds in steel, which comprises the following steps:
electrolyzing and extracting an electrolytic sample, dissolving a matrix, and enriching precipitated phase powder;
analyzing the enriched precipitated phase powder by adopting X-ray diffraction to determine the type of the precipitated phase;
dissolving the carbide by a phase separation method to realize the separation of the carbide from intermetallic compounds and free carbon;
determining the type of the intermetallic compound by adopting X-ray diffraction;
separating free carbon in the intermetallic compound by adopting ultrasonic oscillation;
and observing the morphology of the intermetallic compound by adopting a scanning electron microscope, and carrying out energy spectrum analysis on the intermetallic compound.
Further, the method comprises:
s1, preparing a steel sample to be detected into an electrolysis sample required by electrolysis extraction;
s2, pre-electrolyzing the electrolytic sample and then electrolyzing the electrolytic sample, wherein the method comprises the following steps:
s21, placing the electrolysis sample in a beaker for pre-electrolysis, wherein the current density of the pre-electrolysis is 0.03-0.05A/cm 2 The total current is 0.6-0.7A, and the pre-electrolysis time is 10-15 min;
s22, placing the electrolyzed sample after the pre-electrolysis into an electrolysis device, wherein the current density is 0.03-0.05A/cm 2 Electrolyzing for 1-2 h under the condition that the total current is 0.6-0.7A;
the components of the electrolyte for pre-electrolysis and electrolysis are the same, and the electrolyte comprises lithium chloride, sulfosalicylic acid, glycerol and methanol; before electrolysis, calculating the surface area of a part needing electrolysis during electrolysis according to the total current and the current density during electrolysis, sticking a part not needing electrolysis on an insulating tape, only exposing the surface of the part needing electrolysis, and completely immersing the part needing electrolysis in electrolyte for electrolysis;
s3, after the electrolysis is finished, brushing the precipitated phase powder into a beaker by using a citric acid ethanol solution, filtering the powder in the beaker by using an inlet microporous filter membrane, sequentially washing the powder by using a citric acid ethanol washing solution and a citric acid water washing solution for multiple times respectively, and finally washing the powder by using distilled water and drying the powder;
s4, analyzing the precipitated phase powder by using an X-ray diffractometer to determine the type of the precipitated phase;
s5, removing carbides in precipitated phase powder by adopting a phase separation method: placing the precipitated phase powder in H 2 SO 4 、H 2 O 2 Heating the mixture and citric acid water solution, and keeping the temperature for 10-40 min; dissolving carbide in the precipitated phase powder;
s6, filtering and collecting undissolved precipitated phase powder, cleaning, and analyzing the precipitated phase powder by using an X-ray diffractometer to determine the type of the precipitated phase;
s7, mixing the cleaned precipitated phase powder with distilled water, putting the mixture into a beaker, putting the beaker into ultrasonic waves for ultrasonic dispersion, suspending free carbon on the surface, and concentrating the rest precipitated phase at the bottom of the beaker; wherein the remaining precipitate phase mainly comprises intermetallic compounds;
and S8, after the ultrasound is finished, collecting the precipitated phase at the bottom of the beaker, preparing a scanning electron microscope sample, observing the morphology of the precipitated phase by using the scanning electron microscope, and performing energy spectrum analysis.
Furthermore, in the S2, the proportion of lithium chloride, sulfosalicylic acid, glycerol and methanol in the components of the electrolyte is 8-12g.
Further, in S2, the preparation method of the electrolyte includes: weighing lithium chloride, adding the lithium chloride into methanol, stirring to dissolve the lithium chloride, adding sulfosalicylic acid, stirring to dissolve the sulfosalicylic acid, adding glycerol, stirring uniformly, filling the prepared electrolyte into a reagent bottle, and freezing the reagent bottle for more than 2 hours.
Further, in S22, the calculation formula of the surface area S of the portion to be electrolyzed at the time of electrolysis is: s = total current/current density.
Further, in S21, the method further includes brushing off a precipitated phase attached to the surface of the pre-electrolyzed electrolytic sample, then washing the sample clean, drying the electrolytic sample by blowing, and placing the dried sample in an electrolysis device.
Further, in said S5, H 2 SO 4 、H 2 O 2 And citric acid in water 2 SO 4 、H 2 O 2 And the volume ratio of water to citric acid is 5-8 2 SO 4 And H 2 O 2 The mass-to-volume ratio of the aqueous solution (1) is 10 to 30g.
Further, in S5, the removing carbides from the precipitated phase powder by a phase separation method includes: the precipitated phase powder was added to a beaker, then H was added 2 SO 4 、H 2 O 2 And of citric acidAdding the aqueous solution into a beaker, placing the beaker in a boiling water bath, keeping the temperature for 10-40 min, and supplementing H every 5-8 min in the midway 2 O 2 。
Further, the S8 includes:
s801, after the ultrasonic treatment is finished, taking out the beaker, and sucking the free carbon floating on the upper layer by using a suction pipe;
s802, slightly shaking counterclockwise by hand to concentrate the residual precipitated phase powder at the central position of the bottom of the beaker, replacing a clean suction pipe, sucking the precipitated phase at the bottom of the beaker by using the suction pipe, placing the precipitated phase on a prepared clean glass slide, and after the water on the glass slide is naturally evaporated to dryness, using conductive adhesive to extract the precipitated phase;
and S803, adhering the conductive adhesive adhered with the precipitated phase on a sample holder of a scanning electron microscope, observing the morphology of the precipitated phase by using the scanning electron microscope, and performing energy spectrum analysis.
Further, S5 and S6 are omitted, and S7 is performed directly, in which case both the carbide and the intermetallic compound in the precipitated phase are concentrated at the bottom of the beaker; the precipitated phase at the bottom of the beaker is collected and manufactured into an electron microscope sample, and the morphology observation and the element analysis can be simultaneously carried out on the carbide and the intermetallic compound.
Compared with the prior art, the invention can realize at least one of the following beneficial effects:
a) The method for accurately measuring the type, the morphology and the elemental composition of the intermetallic compound in the steel provided by the invention has the advantages that through electrolytic extraction, matrix dissolution and precipitated phase powder enrichment; analyzing the enriched precipitated phase powder through X-ray diffraction, and accurately measuring diffraction data of the precipitated phase, thereby accurately determining the type of the precipitated phase; then separating carbide and intermetallic compound by phase separation method; determining the type of the intermetallic compound by X-ray diffraction; separating free carbon in the intermetallic compound by adopting ultrasonic oscillation; and observing the morphology of the intermetallic compound by adopting a scanning electron microscope, and carrying out energy spectrum analysis on the intermetallic compound.
b) The method adopts an electrolytic extraction method, and by accurately controlling the components of the electrolyte, the electrolytic conditions, the matrix of the steel is dissolved, the precipitated phase is retained, and no matrix interference exists; only the intermetallic compound is reserved by separating free carbon and carbide, and the scanning electron microscope energy spectrum analysis result of the intermetallic compound is more accurate.
c) The method combines pre-electrolysis and electrolysis, and the pre-electrolysis can electrolyze a layer on the surface of an electrolysis sample, so that the problem of sample pollution caused in the sample preparation process is solved.
d) The method of the invention can prevent the products precipitated by the reduction of the cathode from polluting the precipitated phase by putting the electrolyte into a capsule.
e) The method of the invention filters the electrolyte before electrolysis, and can reduce the influence of impurities in the electrolyte on the detection and observation of intermetallic compounds.
f) The method of the invention can simultaneously carry out morphology observation and element accurate analysis on the carbide and the intermetallic compound without adopting a phase separation method to remove the carbide in the precipitated phase powder.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description.
Drawings
The drawings are only for purposes of illustrating the particular invention and are not to be construed as limiting the invention, wherein like reference numerals are used to designate like parts throughout the figures.
FIG. 1 is a schematic illustration of an electrolytic sample placed in an electrolysis apparatus;
FIG. 2 is an XRD pattern of the precipitated phases in example 1;
FIG. 3a shows M in example 1 6 Morphology of phase C;
FIG. 3b is M in example 1 6 Energy spectrum of phase C;
FIG. 4a is the morphology of the chi phase in example 1, and FIG. 4b is the energy spectrum of the chi phase in example 1;
FIG. 5 is an XRD pattern of the precipitated phase in example 2;
FIG. 6 is the morphology of the precipitated phase in example 2; wherein # 1 is M 12 C,2# is mu phase; 3# isTi(CN)。
FIG. 7a is M in example 2 12 The spectrum of the C phase, FIG. 7b the spectrum of the μ phase in example 2, and FIG. 7C the spectrum of the Ti (CN) phase in example 2.
Reference numerals
1-beaker, 2-cathode, 3-capsule, 4-electrolysis sample.
Detailed Description
The following examples describe the invention in detail. The examples are illustrative and are intended to describe embodiments of the invention and not to limit the scope of the invention.
The precipitated phase in the high alloy steel usually comprises intermetallic compounds, carbides and the like of chi phase and mu phase, and the intermetallic compounds of chi phase and mu phase have no age hardening effect, so that the performance of the steel is reduced, the type, the appearance, the element content and the like of the precipitated phase are accurately analyzed, and the method has certain effect on designing alloy components, selecting a heat treatment system and the like, and avoids the intermetallic compounds of chi phase and mu phase as far as possible. How to accurately analyze the morphology and the elemental composition of intermetallic compounds in steel (especially high alloy steel) is an urgent problem to be solved.
The invention provides a method for accurately measuring the type, morphology and elemental composition of intermetallic compounds in steel, which comprises the following steps: electrolyzing and extracting an electrolytic sample, dissolving a matrix, and enriching precipitated phase powder; analyzing the enriched precipitated phase powder by adopting X-ray diffraction to determine the type of the precipitated phase; then dissolving the carbide by a phase separation method to realize the separation of the carbide from intermetallic compounds and free carbon; determining the type of the intermetallic compound by X-ray diffraction; separating free carbon in the intermetallic compound by adopting ultrasonic oscillation; and observing the appearance of the intermetallic compound by adopting a scanning electron microscope, and carrying out energy spectrum analysis on the intermetallic compound.
Specifically, the method comprises the following steps:
s1, preparing a steel sample to be detected into an electrolysis sample required by electrolysis extraction;
s2, pre-electrolyzing the electrolytic sample and then electrolyzing the electrolytic sample, wherein the pre-electrolyzing comprises the following steps:
S21、placing the electrolysis sample in a beaker for pre-electrolysis, wherein the current density of the pre-electrolysis is 0.03-0.05A/cm 2 Total current is 0.6-0.7A, and the pre-electrolysis time is 10-15 min;
s22, placing the electrolyzed sample after the pre-electrolysis into an electrolysis device, wherein the current density is 0.03-0.05A/cm 2 Electrolyzing for 1-2 h under the condition that the total current is 0.6-0.7A;
the components of the electrolyte for pre-electrolysis and electrolysis are the same, and the electrolyte comprises lithium chloride, sulfosalicylic acid, glycerol and methanol; before electrolysis, calculating the surface area of a part needing electrolysis during electrolysis according to the total current and the current density during electrolysis, sticking a part not needing electrolysis on an insulating tape, only exposing the surface of the part needing electrolysis, and completely immersing the part needing electrolysis in electrolyte for electrolysis;
s3, after the electrolysis is finished, brushing the precipitated phase powder into a beaker by using a citric acid ethanol solution, filtering the powder in the beaker by using an inlet microporous filter membrane, sequentially washing the powder by using a citric acid ethanol washing solution and a citric acid water washing solution for multiple times respectively, and finally washing the powder by using distilled water and drying the powder;
s4, analyzing the precipitated phase powder by using an X-ray diffractometer to determine the type of the precipitated phase;
s5, removing carbides in precipitated phase powder by adopting a phase separation method: placing the precipitated phase powder in H 2 SO 4 、H 2 O 2 Heating the mixture and citric acid water solution, and keeping the temperature for 10-40 min; dissolving carbide in the precipitated phase powder;
s6, filtering and collecting undissolved precipitated phase powder, cleaning, and analyzing the precipitated phase powder by using an X-ray diffractometer to determine the type of the precipitated phase;
s7, mixing the cleaned precipitated phase powder with distilled water, putting the mixture into a beaker, putting the beaker into ultrasonic waves for ultrasonic dispersion, suspending free carbon on the surface, and concentrating the rest precipitated phase at the bottom of the beaker; wherein the remaining precipitate phase mainly comprises intermetallic compounds;
and S8, after the ultrasonic treatment is finished, collecting the precipitated phase at the bottom of the beaker, using conductive adhesive to pick up the precipitated phase, adhering the conductive adhesive with the precipitated phase on a sample rack of a scanning electron microscope, observing the morphology of the gold precipitated phase by using the scanning electron microscope, and performing energy spectrum analysis.
Specifically, in the above S1, the electrolytic sample may be in a rod shape or a sheet shape, and considering that the size of the electrolytic sample is too large, the sample is too long or too thick, and the electrolytic sample is inconvenient to suspend in a capsule for electrolysis, and the total current cannot be too large by using an organic solution for electrolysis, so as to avoid the temperature rise of the electrolyte during the electrolysis process, which causes the loss of an unstable precipitated phase; too small a sample, low total current, too long an electrolysis time to collect a sufficient amount of precipitated phase powder, and the loss of unstable precipitated phase may occur. Thus, the dimensions of the electrolysis samples were controlled as follows: when the rod-shaped product is in a rod shape, the diameter is 5-15 mm, and the length is 60-100 mm; when the sheet is in a sheet shape, the length is 60-100 mm, the width is 15-25 mm, and the thickness is 3-7 mm.
Specifically, in the step S1, a groove with the thickness of 2-4 mm is carved at one end of the electrolysis sample for binding a copper wire, and the electrolysis sample needs to be suspended for electrolysis.
Specifically, in S2, the ratio of lithium chloride, sulfosalicylic acid, glycerol, and methanol in the electrolyte composition is 8 to 12g. Lithium chloride in the electrolyte acts as an electrolyte, making the solution conductive and providing suitable anions, and methanol acts as a solvent. Sulfosalicylic acid is used as a complexing agent to prevent metal ions from being hydrolyzed, high Cr content of high alloy steel is high, pitting corrosion is easy to generate in the electrolytic process, and glycerol is used as a surfactant, so that the electrolytic surface of a sample can be smooth and clean without pitting corrosion after the glycerol is added.
Specifically, in S2, the volume of the beaker during the preliminary electrolysis is 200 to 500ml, for example, 200ml, 300ml, 400ml, 500ml.
Specifically, in S2, the preparation method of the electrolyte includes: weighing lithium chloride, adding the lithium chloride into methanol, stirring to dissolve the lithium chloride, adding sulfosalicylic acid, stirring to dissolve the sulfosalicylic acid, adding glycerol, stirring uniformly, and filling the prepared electrolyte into a reagent bottle. All the reagents are analytically pure. In order to ensure that the precipitated phase is completely reserved during electrolysis and minimize the volatilization of the electrolyte, the electrolysis is required to be carried out at a low temperature below minus 5 ℃, so the reagent bottle is put into a freezing chamber of a refrigerator for freezing for more than 2 hours.
In S2, in the preparation method of the electrolyte, the lithium chloride is added into the methanol first, and is stirred to dissolve, and then the sulfosalicylic acid is added and is stirred to dissolve, so that the lithium chloride and the sulfosalicylic acid can be dissolved sufficiently and quickly, and if the glycerol is added first, the viscosity of the solution becomes high, and the dissolution speed of the lithium chloride and the sulfosalicylic acid becomes slow.
In S2, the current density during electrolysis is too high, and a part of the unstable precipitated phase may be electrolyzed together with the matrix, and the unstable precipitated phase cannot be retained; the current density is too low, so that complete activation and dissolution of the matrix cannot be guaranteed; therefore, the current density is controlled to be 0.03 to 0.05A/cm 2 The total current is generally controlled to be 0.6-0.7A. And calculating the surface area of the part needing electrolysis and the length of the part needing electrolysis according to the total current and the current density during electrolysis. The calculation formula of the surface area S of the portion to be electrolyzed is: s = total current/current density. The sample of the non-electrolysis part was adhered with an insulating tape to expose only the surface of the part to be electrolyzed. The surface area of the part needing electrolysis is controlled, mainly to control the current density in the electrolysis process to be kept between 0.03 and 0.05A/cm 2 Ensuring that the matrix is completely dissolved and the precipitated phase is reserved. Meanwhile, different samples are ensured to adopt the same electrolysis condition, so that the difference of precipitated phases in different samples is compared.
In S2, a semipermeable membrane through which ions can pass can be formed as a capsule because the reduction product of the cathode stains the precipitated phase in order to prevent the electrolysis time from being long.
In order to eliminate the contamination brought by impurities in the chemical agent. In the S2, the electrolyte is filtered by a 0.2 mu m microporous filter membrane in advance before electrolysis; then adding the filtered electrolyte for electrolysis.
Specifically, in S2 above, the method for producing a capsule includes: weighing cellulose acetate, dissolving the cellulose acetate in acetone, pouring the mixed solution onto a mould for preparing capsules after the cellulose acetate is completely dissolved, drying the mixed solution, soaking the mixed solution in water for 2 to 5min, peeling the capsules from the mould, and soaking the capsules in distilled water for later use. Wherein, the proportion of the cellulose acetate and the acetone is 45-50 g:500ml. During the electrolysis process, the capsule allows the normal passing of anions and cations, but precipitated phase powder and the like falling from the electrolysis sample cannot pass through and are collected in the capsule.
Specifically, in S2, as shown in fig. 1, the step of placing the electrolytic sample in the electrolysis apparatus includes:
s201, taking a beaker 1 with the capacity of 500ml as an electrolytic cell, putting sheet-shaped or cylindrical stainless steel into the beaker 1 to serve as a cathode 2, then putting a capsule 3, putting filtered and low-temperature frozen electrolyte into the capsule, then putting the beaker with the electrolyte and the cathode on an electrolytic frame, suspending an electrolytic sample 4 in the electrolyte, and completely immersing the part of the electrolytic sample needing electrolysis in the electrolyte;
s202, placing the electrolysis frame in a freezing chamber of a refrigerator, connecting an electrolysis power supply, connecting a cathode with a cathode, connecting an anode with an electrolysis sample, and electrolyzing after electrifying.
Specifically, in the above S2, the pre-electrolysis is used to electrolyze a layer of the surface of the electrolytic sample (hereinafter, also referred to as "sample"), thereby eliminating the problem of sample contamination caused during the sample preparation process. The problems of too long pre-electrolysis time, too much sample electrolysis loss, too short time, too little sample surface electrolysis amount and incapability of completely eliminating sample surface pollution are solved. Therefore, the pre-electrolysis is controlled for 10-15 min.
Specifically, in S21, the method further includes: taking out the sample after pre-electrolysis, brushing off precipitated phase powder attached to the surface of the sample, washing the sample clean, drying the sample by blowing, calculating the surface area of a part of the sample needing electrolysis, sticking a part of the sample not needing electrolysis on an insulating tape, adopting filtered electrolyte (the electrolyte is unused in order to reduce the influence of impurities in chemical reagents), and putting the sample into an electrolysis device for electrolysis.
Considering that the electrolysis time is too long, the resistance of the electrolyte is increased, the temperature is increased in the electrolysis process, the unstable precipitated phase is not favorably and completely reserved, and the content of lithium chloride and sulfosalicylic acid in the electrolyte is changed due to the too long time, so that the electrolysis effect is influenced. Too short, too little precipitated phase powder is collected, inconvenient observation is realized, and the statistical effect is not good enough. Therefore, in S2, the electrolysis time is controlled to be 1 to 2 hours. During electrolysis, the matrix of the steel dissolves and the precipitated phase remains as insoluble residue powder.
Specifically, in S3, since ions in the electrolyte are likely to be hydrolyzed and precipitated in an ethanol solution without a complexing agent in consideration of the fact that ions in the electrolyte are attached to the surface of the sample, the precipitated phase powder is brushed into a beaker by using a citric acid ethanol solution. Considering that the excessive concentration of citric acid and the strong acidity cause the loss of part of unstable precipitated phases, the too small concentration of citric acid can not effectively clean the ions in the electrolyte attached to the surface of the sample; therefore, the mass volume ratio of the citric acid to the ethanol in the citric acid ethanol solution is controlled to be 5-10 g:1L of the compound.
Specifically, in S3, since the adhered electrolyte is washed with citric acid and ethanol first in consideration of electrolysis with an organic solution, ions or citric acid are more completely dissolved in water, and thus, the electrolyte is washed with citric acid and ethanol washing solutions and citric acid washing solutions in sequence, respectively, for a plurality of times. Wherein the mass volume ratio of citric acid to ethanol in the citric acid ethanol washing solution is 8-15 g:1L of the compound. The mass volume ratio of citric acid to water in the citric acid washing liquid is 8-15 g:1L of the compound.
Specifically, in S4, the diffraction conditions are: the 2 theta is 20-100 degrees, the 5.5mm anti-scattering slit is formed, the step size is 0.0167 degrees, the time is 20 seconds, the array detector is used, the target type is a Cu target, the tube flow is 40kV40mA, diffraction analysis is carried out on precipitated phase powder, the diffraction d value and the relative intensity of the precipitated phase are determined, and therefore precipitated phase structure analysis is carried out.
Specifically, in S5, when a high alloy steel is examined, the precipitated phase powder of the high alloy steel mainly contains free carbon and carbide (M) 6 C、M 12 C. Carbide phases rich in W, mo, nb, ti, such as MC) and intermetallic compounds (e.g., chi phase and μ phase); considering that the carbide can be dissolved in H 2 SO 4 、H 2 O 2 And citric acid, while free carbon and intermetallic compounds are insoluble; thus, using H 2 SO 4 、H 2 O 2 And citric acid, to dissolve carbide and to realize the intermetallic and free carbonAnd (3) separating the compound.
Specifically, in the above-mentioned S5, H 2 SO 4 、H 2 O 2 And citric acid in water 2 SO 4 、H 2 O 2 And water in a volume ratio of 5-8. Citric acid and H 2 SO 4 And H 2 O 2 The mass volume ratio of the aqueous solution of (2) is 10-30 g:1L of, wherein H 2 SO 4 Is commercially available concentrated sulfuric acid with the mass fraction of 98 percent; h 2 O 2 Is commercially available and has a mass fraction of 30%.
Specifically, in S5, the removing of the carbide in the precipitated phase powder by the phase separation method includes: adding the precipitated phase powder into a beaker, adding about 30ml of distilled water, and then adding 15-25 ml of H 2 O 2 Passivating the intermetallic compound of chi phase and mu phase, and then adding 5-8 ml of concentrated H 2 SO 4 After being stirred evenly, 1-3 g of citric acid is added, after being stirred to be dissolved, distilled water is added to dilute the solution to 100ml, the beaker is placed in a boiling water bath to keep the temperature for 10-40 min, and 3-5 ml of H is added every 5-8 min midway 2 O 2 Is supplemented with H 2 O 2 Because of H during heating 2 O 2 Will decompose to ensure H in the solution during the separation process 2 O 2 The amount remained unchanged.
Specifically, in S7, considering that free carbon affects elemental analysis of the intermetallic compound, the cleaned precipitated phase powder is mixed with distilled water and placed in a beaker, the beaker is placed in ultrasonic waves for ultrasonic dispersion, the density of the free carbon is less than that of water, and therefore the free carbon is suspended on the surface, and the remaining precipitated phase is concentrated at the bottom of the beaker; wherein the remaining precipitate phase mainly comprises intermetallic compounds; the intermetallic compound is denser than water and therefore concentrates at the bottom of the beaker.
Specifically, in the step S7, the ultrasound time is too long, the efficiency is low, and energy is wasted; the time is too short, and the separation effect of the free carbon and the intermetallic compound is poor, so the ultrasonic time is controlled to be 5-10 min.
Specifically, the specific process of S8 includes:
s801, after the ultrasonic treatment is finished, taking out the beaker, and sucking the free carbon floating on the upper layer by using a suction pipe;
s802, slightly shaking counterclockwise by hand to concentrate the remaining precipitated phase at the central position of the bottom of the beaker, replacing a clean suction pipe, sucking the precipitated phase at the bottom of the beaker by using the suction pipe, placing the precipitated phase on a prepared clean glass slide, and after the water on the glass slide is naturally evaporated to dryness, using conductive adhesive to extract the precipitated phase;
and S803, adhering the conductive adhesive adhered with the precipitated phase on a sample holder of a scanning electron microscope, observing the morphology of the precipitated phase by using the scanning electron microscope, and performing energy spectrum analysis.
In order to analyze the type of precipitated phase in the steel in detail, in S4, the precipitated phase powder is analyzed by an X-ray diffractometer, and after the type of precipitated phase is determined, the morphology of the precipitated phase powder can be observed by a scanning electron microscope.
In order to analyze the carbide composition in the steel in detail, S5 and S6 may be omitted and S7 may be performed as it is, in which case both the carbide and the intermetallic compound are concentrated in the bottom of the beaker; the carbide and the intermetallic compound at the bottom of the beaker are collected and manufactured into an electron microscope sample, and the morphology observation and the element analysis can be simultaneously carried out on the carbide and the intermetallic compound.
Compared with the prior art, the method for accurately measuring the type, the appearance and the element composition of the intermetallic compounds in the steel has the advantages that through electrolytic extraction, matrix dissolution and precipitated phase powder enrichment; analyzing the enriched precipitated phase powder through X-ray diffraction, and accurately measuring diffraction data of the precipitated phase, thereby accurately determining the type of the precipitated phase; then separating carbide and intermetallic compound by phase separation method; determining the type of the intermetallic compound by adopting X-ray diffraction; separating free carbon in the intermetallic compound by adopting ultrasonic oscillation; and observing the morphology of the intermetallic compound by adopting a scanning electron microscope, and carrying out energy spectrum analysis on the intermetallic compound. By accurately controlling the components and electrolysis conditions of the electrolyte, the matrix of the steel is dissolved, and a precipitated phase is retained without matrix interference; and only the intermetallic compound is reserved by separating free carbon and carbide, so that the scanning electron microscope energy spectrum analysis result of the intermetallic compound is more accurate.
The method combines pre-electrolysis and electrolysis, and the pre-electrolysis can electrolyze a layer of the surface of an electrolysis sample, so that the problem of sample pollution caused in the sample preparation process is solved.
The method of the present invention, in which the electrolyte is encapsulated, prevents the reduction product of the cathode from contaminating the precipitated phase.
The method of the invention filters the electrolyte before electrolysis, and can reduce the influence of impurities in the electrolyte on the detection and observation of intermetallic compounds.
The method of the invention can simultaneously carry out morphology observation and element accurate analysis on the carbide and the intermetallic compound without adopting a phase separation method to remove the carbide in the precipitated phase powder.
The method of the present invention for accurately determining intermetallic compound type, morphology and elemental composition in steel will be shown below in specific examples.
Example 1
The embodiment provides a method for accurately measuring the types, the appearances and the element compositions of intermetallic compounds in high-temperature bearing steel (the mass percent of all components is 0.1-0.2%, 12-16% of Cr, 11-13% of Co, 4-6% of Mo, 1.5-2.5% of Ni, 0.15-0.25% of W, 0.15-0.25% of V, and the balance of Fe and inevitable impurities). The method comprises the following steps:
(1) Preparing an electrolysis sample required by electrolysis extraction, wherein the electrolysis sample is rod-shaped and has the size of 10mm x 80mm, and a 2mm groove is engraved at one end of the electrolysis sample and is used for binding a copper wire.
(2) Preparing an electrolyte: weighing 10g of lithium chloride, adding the lithium chloride into 950ml of methanol, stirring and dissolving, then adding 40g of sulfosalicylic acid, stirring and dissolving, then adding 50ml of glycerol, stirring uniformly, then filling into a reagent bottle, and putting the reagent bottle into a refrigerator freezing chamber for freezing for 2 hours;
(3) Preparing capsules: weighing 45g of cellulose acetate, dissolving the cellulose acetate in 500ml of acetone, pouring the capsule liquid on a capsule making mold after the cellulose acetate is completely dissolved uniformly, airing, soaking in water for 2-5 min, peeling the capsule from the mold, and soaking in distilled water for later use;
(4) Firstly adding an electrolyte into a 200ml beaker, putting the beaker into a cathode, pre-electrolyzing for 10min, then brushing off precipitated phase powder attached to the surface of a sample, then washing the sample, drying the sample by blowing, calculating the surface area of an electrolytic part of the sample, and then sticking a nonelectrolytic part on the sample by using an insulating tape. Taking a beaker 1 with the capacity of 500ml as an electrolytic cell, putting cylindrical stainless steel into the beaker 1 as a cathode 2, then putting a capsule 3, putting the filtered and low-temperature frozen electrolyte into the capsule, then putting the beaker with the electrolyte and the cathode on an electrolytic frame, suspending an electrolytic sample 4 in the electrolyte, and enabling the part of the electrolytic sample needing to be electrolyzed to be 15cm 2 Completely immersed in the electrolyte; placing the electrolysis frame in a refrigerator freezing chamber, connecting with a power supply for electrolysis, connecting a cathode with a cathode and an anode with an electrolysis sample, suspending the electrolysis sample in an electrolyte for electrolysis for 1h, wherein the current density during pre-electrolysis and electrolysis is 0.04A/cm 2 The total current was 0.6A. During electrolysis, the matrix dissolves and the precipitated phase remains as insoluble residue.
(5) Turning off a power supply after electrolysis, taking out an electrolyzed sample after electrolysis, putting the electrolyzed sample into a 250ml beaker, directly brushing the non-fallen precipitated phase powder into the beaker by using 5-10 g/L citric acid ethanol solution for the sample, carrying out suction filtration on the precipitated phase powder in the beaker together with the precipitated phase powder falling into the capsule by using an inlet microporous filter membrane, sequentially washing the separated phase powder for 3 times by using washing liquid containing 10g/L citric acid ethanol and 10g/L citric acid water respectively, finally washing residues by using distilled water, and drying;
(6) And (3) measuring the diffraction spectrum peak of the precipitated phase by using an X-ray diffractometer, wherein the diffraction conditions are as follows: 2 theta is 20-100 degrees, 5.5mm anti-scattering slits are formed, the step size is 0.0167 degrees, the time is 20 seconds, an array detector is arranged, the target type is a Cu target, the tube pressure tube flow is 40kV40mA, diffraction analysis is carried out on precipitated phase powder, the diffraction d value and the relative intensity of a precipitated phase are determined, and therefore precipitated phase structure analysis is carried out; the analysis shows that the precipitated phase mainly comprises M 6 C and chi phases;
(7) By usingObserving the morphology of the precipitated phase by a scanning electron microscope; as shown in FIG. 3, is M 6 Morphology of phase C.
(8) Removing carbides in precipitated phase powder by adopting a phase separation method: putting the precipitated phase powder in H 2 SO 4 、H 2 O 2 Heating in water solution of citric acid (placing the beaker in boiling water bath), and keeping the temperature for 10-40 min; dissolving carbide in the precipitated phase powder; wherein H 2 SO 4 And H 2 O 2 H in the aqueous solution of (1) 2 SO 4 、H 2 O 2 And water in a volume ratio of 6; citric acid and H 2 SO 4 And H 2 O 2 The mass-to-volume ratio of the aqueous solution (2) to (1) is 20g;
(9) Carrying out suction filtration to collect undissolved precipitated phase powder, cleaning, and analyzing the precipitated phase powder by using an X-ray diffractometer to determine the type of the precipitated phase; analyzing to obtain a precipitated phase which mainly comprises a chi phase;
(10) Mixing the clean precipitated phase powder with distilled water, putting the mixture into a beaker, putting the beaker into ultrasonic waves for ultrasonic dispersion, suspending free carbon on the surface, and concentrating intermetallic compounds at the bottom of the beaker;
(11) After the ultrasonic treatment is finished, taking out the beaker, and sucking the free carbon floating on the upper layer by using a suction pipe; then slightly shaking counterclockwise by hand to concentrate the intermetallic compound powder at the central position of the bottom of the beaker, replacing a clean suction pipe, sucking the intermetallic compound powder at the bottom of the beaker by using the suction pipe, placing the intermetallic compound powder on a prepared clean glass slide, and after the water on the glass slide is naturally evaporated to dryness, using conductive adhesive to pick up the intermetallic compound powder; and adhering the conductive adhesive adhered with the intermetallic compound on a sample holder of a scanning electron microscope, observing the morphology of the intermetallic compound by using the scanning electron microscope, and performing energy spectrum analysis.
FIG. 2 shows an XRD pattern of the precipitated phase, and FIG. 3a shows M 6 Morphology of phase C; FIG. 3b is M 6 Energy spectrum of phase C; as shown in fig. 4a, the morphology of the intermetallic chi-phase, and fig. 4b is the spectrum of the chi-phase; it can be seen that the precipitated phase in the high-temperature bearing steel is mainly M 6 C and chi phases. M 6 Ratio of CThe carbide is fine and granular, and is a stable carbide precipitated by high-temperature aging; the chi phase was relatively coarse and blocky in morphology, and spectral analysis found that the major elements in the phase were Fe, mo, cr, co and W, but the Fe content was significantly higher than Mo (fig. 4 b).
Example 2
The embodiment provides a method for accurately measuring the types, the shapes and the element compositions of intermetallic compounds in a nickel-base superalloy (the components comprise, by mass, 0.04-0.05% of C, 18-21% of Cr, 7-9% of Mo, 7-9% of W, 0.5-0.7% of Ti, 0.5-0.6% of Al, 1.5-1.8% of Fe, 0.15-0.18% of Mn, 0.020-0.025% of N and the balance of Ni and inevitable impurities), and the method is adopted to analyze precipitated phases in the high-temperature alloy steel. The method comprises the following steps:
(1) Preparing an electrolysis sample required by electrolysis extraction, wherein the electrolysis sample is rod-shaped and has the size of 10mm x 80mm, and a 2mm groove is engraved at one end of the electrolysis sample and is used for binding a copper wire.
(2) Preparing an electrolyte: weighing 10g of lithium chloride, adding the lithium chloride into 950ml of methanol, stirring and dissolving, then adding 40g of sulfosalicylic acid, stirring and dissolving, then adding 50ml of glycerol, stirring uniformly, then filling into a reagent bottle, and putting the reagent bottle into a refrigerator freezing chamber for freezing for 2 hours;
(3) Preparing capsules: weighing 45g of cellulose acetate, dissolving the cellulose acetate in 500ml of acetone, pouring the capsule liquid on a capsule making mold after the cellulose acetate is completely dissolved uniformly, airing, soaking in water for 2-5 min, peeling the capsule from the mold, and soaking in distilled water for later use;
(4) Firstly adding an electrolyte into a 200ml beaker, putting a cathode into the beaker, pre-electrolyzing for 10min, then brushing off precipitated phase powder attached to the surface of a sample, then washing the sample clean, drying the sample by blowing, calculating the surface area of an electrolytic part of the sample, and then sticking a nonelectrolytic part on the sample by using an insulating tape. Taking a beaker 1 with the capacity of 500ml as an electrolytic cell, putting cylindrical stainless steel into the beaker 1 as a cathode 2, then putting a capsule 3, putting filtered and frozen electrolyte at low temperature into the capsule, then putting the beaker with the electrolyte and the cathode on an electrolytic frame, suspending an electrolytic sample 4 in the electrolyte, and enabling the electrolytic sample to need electricitySolution part 14cm 2 Completely immersed in the electrolyte; placing the electrolysis frame in a refrigerator freezing chamber, connecting with a power supply for electrolysis, connecting a cathode with a cathode, connecting an anode with an electrolysis sample, suspending the electrolysis sample in an electrolyte for electrolysis for 1h, wherein the current density during pre-electrolysis and electrolysis is 0.05A/cm 2 Total current 0.7A. During electrolysis, the matrix dissolves and the precipitated phase remains as insoluble residue.
(5) Turning off a power supply after electrolysis, taking out an electrolyzed sample after electrolysis, putting the electrolyzed sample into a 250ml beaker, directly brushing the powder of a precipitated phase which does not fall off into the beaker by using 5-10 g/L citric acid ethanol solution for the sample, carrying out suction filtration on the powder of the precipitated phase in the beaker and the powder of the precipitated phase which falls into a capsule by using an inlet microporous filter membrane, sequentially washing the powder of the precipitated phase by using washing liquor containing 10g/L citric acid ethanol and 10g/L citric acid water for 3 times, finally washing residues by using distilled water, and drying;
(6) And (3) measuring the diffraction spectrum peak of the precipitated phase by using an X-ray diffractometer, wherein the diffraction conditions are as follows: 2 theta is 20-100 degrees, 5.5mm anti-scattering slits are formed, the step size is 0.0167 degrees, the time is 20 seconds, an array detector is arranged, the target type is a Cu target, the tube pressure tube flow is 40kV40mA, diffraction analysis is carried out on precipitated phase powder, the diffraction d value and the relative intensity of a precipitated phase are determined, and therefore precipitated phase structure analysis is carried out; the analysis shows that the precipitated phase mainly comprises M 12 C. Ti (CN) and a mu phase;
(7) Mixing precipitated phase powder with distilled water, putting the mixture into a beaker, putting the beaker into ultrasonic waves for ultrasonic dispersion, suspending free carbon on the surface, and concentrating carbide and intermetallic compounds at the bottom of the beaker;
(8) After the ultrasonic treatment is finished, taking out the beaker, and sucking the free carbon floating on the upper layer by using a suction pipe; then slightly shaking counterclockwise by hand to concentrate the residual precipitated phase powder (mainly comprising carbide and intermetallic compounds) at the central position of the bottom of the beaker, replacing a clean suction pipe, sucking the precipitated phase powder at the bottom of the beaker by using the suction pipe, placing the precipitated phase powder on a prepared clean glass slide, and after the water on the glass slide is naturally evaporated to dryness, using conductive adhesive to take the precipitated phase powder; and adhering the conductive adhesive adhered with the precipitated phase powder on a sample holder of a scanning electron microscope, observing the morphology of the precipitated phase powder by using the scanning electron microscope, and performing energy spectrum analysis.
FIG. 5 shows an XRD pattern of the precipitated phase, FIG. 6 shows the morphology of the precipitated phase, and FIG. 7a shows carbide M 12 Energy spectrum of C phase, FIG. 7b energy spectrum of μ phase, FIG. 7C energy spectrum of Ti (CN); it can be seen that the precipitated phase in the high-temperature alloy steel is mainly M 12 C. Ti (CN) and a mu phase. M 12 C is fine and granular, ti (CN) is square block, M 12 C and Ti (CN) are stable carbides precipitated by high-temperature aging; the particles of the mu phase are relatively coarse and are in the shape of long blocks, and the energy spectrum analysis shows that the main elements in the phases are Ni, mo, W and Cr, but the content of Cr in the mu phase is obviously higher than that of M 12 And C phase.
Therefore, the loss of precipitated phases prepared by the method is less, the quantity of the collected precipitated phases is more, and the morphology and the energy spectrum of carbides and intermetallic compounds can be accurately analyzed by separating free carbon; by separating the carbide and the intermetallic compound, the carbide and the intermetallic compound can be accurately analyzed.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention.
Claims (6)
1. A method for accurately determining intermetallic compound type, morphology and elemental composition in steel, the method comprising:
s1, preparing a steel sample to be detected into an electrolysis sample required by electrolysis extraction;
s2, pre-electrolyzing the electrolytic sample and then electrolyzing the electrolytic sample, wherein the pre-electrolyzing comprises the following steps:
s21, placing the electrolysis sample in a beaker for pre-electrolysis, wherein the current density of the pre-electrolysis is 0.03-0.05A/cm 2 The total current is 0.6-0.7A, and the pre-electrolysis time is 10-15 min;
s22, placing the electrolyzed sample after the pre-electrolysis inIn the electrolysis apparatus, the current density is 0.03-0.05A/cm 2 Electrolyzing for 1-2 h under the condition that the total current is 0.6-0.7A;
the components of the electrolyte for pre-electrolysis and electrolysis are the same, and the electrolyte comprises lithium chloride, sulfosalicylic acid, glycerol and methanol; before electrolysis, calculating the surface area of a part needing electrolysis during electrolysis according to the total current and the current density during electrolysis, sticking a part not needing electrolysis on an insulating tape, only exposing the surface of the part needing electrolysis, and completely immersing the part needing electrolysis in electrolyte for electrolysis;
in S2, the preparation method of the electrolyte comprises the following steps: weighing lithium chloride, adding the lithium chloride into methanol, stirring and dissolving, then adding sulfosalicylic acid, stirring and dissolving, then adding glycerol, stirring uniformly, filling the prepared electrolyte into a reagent bottle, and freezing the reagent bottle for more than 2 hours;
in the S2, the electrolyte is filtered by a 0.2 mu m microporous filter membrane in advance before electrolysis; then adding the filtered electrolyte for electrolysis;
s3, after the electrolysis is finished, brushing the precipitated phase powder into a beaker by using a citric acid ethanol solution, filtering the powder in the beaker by using an inlet microporous filter membrane, sequentially washing the powder by using a citric acid ethanol washing solution and a citric acid water washing solution for multiple times respectively, and finally washing the powder by using distilled water and drying the powder; the mass volume ratio of citric acid to ethanol in the citric acid ethanol washing liquor is 8-15 g:1L, wherein the mass volume ratio of citric acid to water in the citric acid washing solution is 8-15 g:1L;
s4, analyzing the precipitated phase powder by using an X-ray diffractometer to determine the type of the precipitated phase;
s5, removing carbides in precipitated phase powder by adopting a phase separation method: putting the precipitated phase powder in H 2 SO 4 、H 2 O 2 Heating in water solution of citric acid, and keeping the temperature for 10-40 min; dissolving carbide in the precipitated phase powder;
s6, filtering and collecting undissolved precipitated phase powder, cleaning, and analyzing the precipitated phase powder by using an X-ray diffractometer to determine the type of the precipitated phase;
s7, mixing the cleaned precipitated phase powder with distilled water, putting the mixture into a beaker, putting the beaker into ultrasonic waves for ultrasonic dispersion, suspending free carbon on the surface, and concentrating the rest precipitated phase at the bottom of the beaker; wherein the remaining precipitate phase mainly comprises intermetallic compounds; the ultrasonic time is 5-10 min;
s8, after the ultrasonic treatment is finished, collecting a precipitated phase at the bottom of the beaker, preparing a scanning electron microscope sample, observing the morphology of the precipitated phase by using a scanning electron microscope, and performing energy spectrum analysis;
in S5, precipitated phase powder mainly comprises free carbon, carbide and intermetallic compounds, wherein the carbide comprises carbide phases rich in W, mo, nb and Ti; the method for removing the carbide in the precipitated phase powder by adopting a phase separation method comprises the following steps: adding the precipitated phase powder into a beaker, adding about 30ml of distilled water, and then adding 15-25 ml of H 2 O 2 Then adding 5-8 ml of concentrated H 2 SO 4 After being stirred evenly, 1-3 g of citric acid is added, after being stirred to be dissolved, distilled water is added to dilute the solution to 100ml, the beaker is placed in a boiling water bath to keep the temperature for 10-40 min, and 3-5 ml of H is added every 5-8 min midway 2 O 2 ；
The S8 comprises the following steps:
s801, after the ultrasonic treatment is finished, taking out the beaker, and sucking the free carbon floating on the upper layer by using a suction pipe;
s802, slightly shaking counterclockwise by hand to concentrate the residual precipitated phase powder at the central position of the bottom of the beaker, replacing a clean suction pipe, sucking the precipitated phase at the bottom of the beaker by using the suction pipe, placing the precipitated phase on a prepared clean glass slide, and after the water on the glass slide is naturally evaporated to dryness, using conductive adhesive to extract the precipitated phase;
and S803, adhering the conductive adhesive adhered with the precipitated phase on a sample holder of a scanning electron microscope, observing the morphology of the precipitated phase by using the scanning electron microscope, and performing energy spectrum analysis.
2. The method according to claim 1, wherein in the S2, the ratio of lithium chloride, sulfosalicylic acid, glycerol and methanol in the components of the electrolyte is 8-12g.
3. The method according to claim 1, wherein in S22, the calculation formula of the surface area S of the part needing electrolysis during electrolysis is as follows: s = total current/current density.
4. The method according to claim 1, wherein in S21, the method further comprises brushing off precipitated phases attached to the surface of the pre-electrolyzed sample, washing the washed sample, drying the electrolyzed sample by blowing, and placing the dried sample in the electrolysis device.
5. The method of claim 1, wherein in S5, H 2 SO 4 、H 2 O 2 And citric acid in water 2 SO 4 、H 2 O 2 And the volume ratio of water to citric acid is 5-8 2 SO 4 And H 2 O 2 The mass-to-volume ratio of the aqueous solution (1) is 10 to 30g.
6. The method according to claim 1, wherein S7 is performed directly with S5 and S6 omitted, and both carbide and intermetallic compound in the precipitated phase are concentrated at the bottom of the beaker; the precipitated phase at the bottom of the beaker is collected and manufactured into an electron microscope sample, and the morphology observation and the element analysis can be simultaneously carried out on the carbide and the intermetallic compound.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110873213.5A CN113466271B (en) | 2021-07-30 | 2021-07-30 | Method for accurately determining type, morphology and elemental composition of intermetallic compounds in steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110873213.5A CN113466271B (en) | 2021-07-30 | 2021-07-30 | Method for accurately determining type, morphology and elemental composition of intermetallic compounds in steel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113466271A CN113466271A (en) | 2021-10-01 |
| CN113466271B true CN113466271B (en) | 2022-12-16 |
Family
ID=77883381
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110873213.5A Active CN113466271B (en) | 2021-07-30 | 2021-07-30 | Method for accurately determining type, morphology and elemental composition of intermetallic compounds in steel |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113466271B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112553679B (en) * | 2020-11-03 | 2024-02-09 | 中国航发北京航空材料研究院 | Method for separating harmful phase monomer from isothermal forging die material for turbine disk |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105738188B (en) * | 2016-02-29 | 2018-07-06 | 兰州理工大学 | The separation method of non-metallic inclusion in Inconel625 series of high temperature alloys |
| CN106645245B (en) * | 2017-02-27 | 2020-02-07 | 江阴兴澄特种钢铁有限公司 | Electrolytic extraction and determination method for non-metallic inclusions in steel |
| CN106840802A (en) * | 2017-03-09 | 2017-06-13 | 北京科技大学 | A kind of original appearance analysis method of electrolytic separation high-carbon steel inclusion |
| CN107328619B (en) * | 2017-06-07 | 2020-11-06 | 北京科技大学 | Method for separating non-metallic inclusions and carbides in steel inclusions |
| JP6943264B2 (en) * | 2019-03-15 | 2021-09-29 | Ｊｆｅスチール株式会社 | A method for collecting inclusions and / or precipitates in a metal sample, a method for analyzing inclusions and / or precipitates in a metal sample, and an electrolytic solution. |
-
2021
- 2021-07-30 CN CN202110873213.5A patent/CN113466271B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN113466271A (en) | 2021-10-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106645245B (en) | Electrolytic extraction and determination method for non-metallic inclusions in steel | |
| CN102213654B (en) | Electrolytic extraction and detection method of nonmetallic inclusion in steel by utilizing organic solution | |
| CN102538703B (en) | Method for extracting and observing three-dimensional appearance of non-metallic inclusion in steel in full-scale mode | |
| JP4659829B2 (en) | Method to produce high purity nickel | |
| JP4567699B2 (en) | Metal uranium production method | |
| CN105738188A (en) | Separation method for nonmetallic inclusions in Inconel625-series high-temperature alloy | |
| CN107607567B (en) | Quantitative characterization method for nonmetallic inclusions in nickel-based superalloy powder | |
| CN109777968A (en) | A kind of preparation method of used in electronic industry High Purity Gold | |
| CN113466271B (en) | Method for accurately determining type, morphology and elemental composition of intermetallic compounds in steel | |
| Maja et al. | Zinc electrocrystallization from impurity‐containing sulfate baths | |
| CN116818482A (en) | Electrolytic extraction analysis method for precipitated phase in cobalt-based superalloy | |
| CN107084870B (en) | The detection method of sulfur-bearing field trash in a kind of steel | |
| CN102345140A (en) | Method for electrowinning and recovering silver from silver-containing waste catalyst | |
| TW201217542A (en) | Valuable metal recovery method from lead-free waste solder | |
| CN113447509B (en) | Sample preparation method of scanning electron microscope sample for inclusions in rare earth weathering steel | |
| CN103884550B (en) | A kind of method that oxide in steel is analyzed by electroextraction | |
| CN116818483A (en) | Quantitative analysis sample dissolving method for high-stability precipitated phase in high-carbon steel | |
| CN112763296B (en) | Three-dimensional etching method for chromium-manganese stainless steel inclusions | |
| JP2005036245A (en) | Process for electrochemical decomposition of precursors in powder form and electrolysis cell suitable therefor | |
| CN109055981A (en) | A kind of lead anode slurry wash water impurity removal process | |
| CN111879835B (en) | Device and method for nondestructively extracting inclusions in steel | |
| CN117110129B (en) | Quantitative determination method for trace phase mass fraction in nickel-based powder superalloy | |
| CN110161066B (en) | Method for extracting inclusions in steel through non-aqueous solution electrolysis | |
| Clarke et al. | IMPROVED APPARATUS FOR MICRO-ELECTROANALYSIS1 | |
| JPS5937781B2 (en) | Method and apparatus for electrolytic extraction separation of nonmetallic inclusions in a large amount of metal sample |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |