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CN-122015722-A - Calculation method and verification method for strip widths of strip tissues in steel

CN122015722ACN 122015722 ACN122015722 ACN 122015722ACN-122015722-A

Abstract

The invention discloses a calculation method and a verification method for the strip width of a strip tissue in steel, which belong to the technical field of microscopic performance analysis of metal material samples, and the calculation method comprises the following steps of obtaining a metal film sample to be detected, placing the metal film sample under an electron microscope for observation, selecting a proper view field to fully focus the strip tissue, shooting a projection image of the strip beam of the metal film for the first time from the direction of the strip beam of the metal film, and utilizing software carried by the electron microscope to measure the projection image of the strip beam of the metal film for the first time; the sample table is tilted for N degrees, the strip morphology is shot for the second time, the projection image of the metal film strip bundle is measured for the second time, and the actual width of the strip tissue strip in the steel is obtained through calculation by adopting the cosine theorem. According to the method, the projection value of the width of the strip is measured through the inclination angle, the actual value of the width of the strip and the projection angle are calculated by combining the cosine theorem, and a strip width calculation formula is established.

Inventors

  • YAN PINGYUAN
  • ZHONG LILI
  • YU JIAYAO
  • XU RONGJIE
  • WANG TING
  • MA HUIXIA

Assignees

  • 鞍钢股份有限公司

Dates

Publication Date
20260512
Application Date
20260209

Claims (7)

  1. 1. A method for calculating the width of a lath tissue lath in steel is characterized by comprising the following steps: obtaining a metal film sample to be detected; Placing a metal film sample under an electron microscope for observation, focusing a lath tissue by selecting a view field, shooting a projection image of the metal film lath beam for the first time from the direction perpendicular to the lath beam, and measuring the projection image of the metal film lath beam for the first time by utilizing the electron microscope; Keeping the position of the metal film unchanged, tilting the sample stage by N degrees, selecting a field of view to focus the lath tissue, then shooting the lath shape for the second time, and measuring the projection image of the lath bundle of the metal film for the second time; based on the first measured slat bundle projection image and the second measured slat bundle projection image, the actual width of the slat tissue slat in the steel is calculated by adopting the cosine theorem.
  2. 2. The method for calculating the width of the strip tissue strip in steel according to claim 1, wherein the metal film sample is a metal disc with the thickness of 50-60 μm and the diameter of 2-4mm, and the center of the metal disc is perforated by electrolytic double spray thinning to form a center hole.
  3. 3. The method for calculating the width of a strip of tissue of the strip type in steel according to claim 1, wherein the field of view is required to meet the following conditions: The thickness of the central hole at the thinning position is below 100nm; the surface of the thinned part of the central hole has no pollution source; The center hole is thinned without extinction streaks.
  4. 4. A method of calculating the strip width of a strip of steel sheet tissue as set forth in claim 1 wherein-15 < N < +15.
  5. 5. The method for calculating the width of the strip tissue strip in steel according to claim 1, wherein the process of calculating the actual width of the strip tissue strip in steel by adopting a cosine law based on the first measured strip beam projection image and the second measured strip beam projection image is as follows: acquiring a lath width value A and a thickness B of a metal film sample in a projection image of the lath for the first time, According to the cosine law: (1) Wherein: the included angle between the measured width and the actual width of the lath bundles is C, the actual value of the lath width; Due to C 2 =A 2 +B 2 , it is possible to obtain: (2) acquiring a slat bundle width value A 1 in a projection image of the second measurement slat bundle; after the sample stage is tilted by + N, (3) Using cosine and formula: (4) From formulas (2), (3) and (4), known as A and A 1 , the calculation formula of the actual value C of the slat width is obtained by triangle identity and algebraic derivation, as follows: (5)。
  6. 6. the method for verifying the method for calculating the strip width of the strip tissue in steel according to any one of claims 1 to 5, comprising the following steps: The position of the metal film is kept unchanged, the sample table is reversely tilted for N degrees, a third photographing of a strip morphology photo is carried out on the metal film strip beam, and a third measurement is carried out on a projection image of the metal film strip beam, so that a strip beam width value A 2 in the projection image of the strip beam is obtained; calculating a slat width value A ' 2 in a projection image of the third measurement slat by triangle identity and algebraic pushdown based on the slat width actual value C; Comparing the value A 2 of the width of the slat in the projection image of the third measuring slat obtained by measurement with the value A ' 2 of the width of the slat in the projection image of the third measuring slat, when When the threshold value M is exceeded, that is, the calculation method of the strip tissue strip width in the steel is proved to be accurate, when When the threshold value M is not less than the threshold value M, the strip width measurement of the strip-like tissue strip in the steel is performed again.
  7. 7. The method for verifying the width of a strip of steel strip tissue according to claim 6, wherein M is 10-12nm.

Description

Calculation method and verification method for strip widths of strip tissues in steel Technical Field The invention belongs to the technical field of microscopic performance analysis of metal material samples, and relates to a calculation method and a verification method for the width of a strip tissue strip in steel. Background The lath-like structure of steel is mainly lath martensite, lath bainite and pearlite (lamellar). Wherein, the lath martensite has high strength and high plasticity, and has wide application in fields such as quenched and tempered steel, ultra-high strength steel, stainless steel and the like. Lath bainitic steels are also more widely used for their excellent strength, toughness and weldability. Whether lath martensite or bainite, the size of the lath bundles directly affects the strength, toughness, plasticity, and weldability of the steel. The core practical significance of measuring the plate strip martensite and the plate strip bainite in steel is that the method is a bridge for connecting production process parameters and the performances of the final material. From the measurements, the results of the process execution (what organization was obtained) can be known, and thus the properties of the material can be predicted or explained. It is a necessary means for optimizing the production process and ensuring the quality and consistency of the product. Without accurate measurement, it is impossible to determine whether the process is effective and whether the product is acceptable. It is a scientific basis for understanding and improving the properties of materials and developing new materials. Key data is provided for establishing quantitative relationships and exploring new mechanisms. It is an important tool for diagnosing material failure and improving the reliability of products. Therefore, the precise qualitative and quantitative characterization of plate strip martensite and plate strip bainite in steel plays an indispensable role in the production, application and research and development of steel materials. Because lath widths of laths martensite, bainite, pearlite, etc. are typically between tens of nanometers and hundreds of nanometers, and portions of the lath interfaces are blurred, observation and statistical analysis can only be performed using transmission electron microscopy. Related measurement methods have not been searched for at present. Therefore, a method for accurately measuring the widths of the nanoscale laths tissue laths is explored, the widths of the laths are measured in a standardized manner, and the method has a certain guiding significance for developing steel types and adjusting mechanical properties. Disclosure of Invention In order to solve the problem that the prior method for carrying out observation and statistical analysis by using a transmission electron microscope only can carry out determination and has inaccurate calculation, the invention adopts the technical scheme that the method for calculating the widths of the strip tissue strips in the steel comprises the following steps: obtaining a metal film sample to be detected; placing a metal film sample under an electron microscope for observation, selecting a proper view field to fully focus the lath tissue, then shooting a projection image of the lath bundle of the metal film for the first time from the direction perpendicular to the lath bundle, and measuring the projection image of the lath bundle of the metal film for the first time by using the electron microscope; The position of the metal film is kept unchanged, the sample stage is tilted for N degrees, a proper view field is selected to fully focus the lath tissues, then the second shooting is carried out on the plate bar appearance, and the second measurement is carried out on the projection image of the lath bundle of the metal film; based on the first measured slat bundle projection image and the second measured slat bundle projection image, the actual width of the slat tissue slat in the steel is calculated by adopting the cosine theorem. And the metal film sample is a metal wafer with the thickness of 50-60 mu m and the diameter of 2-4mm, and the center of the metal wafer is perforated by electrolytic double-spray thinning to form a center hole. Further, the appropriate field of view needs to meet the following conditions: The thickness of the central hole at the thinning position is below 100nm; the surface of the thinned part of the central hole has no pollution source; The center hole is thinned without extinction streaks. Further, -15 ° < N < +15°. Further, the process of calculating the actual width of the plate tissue strip in the steel by adopting the cosine law based on the first measured strip beam projection image and the second measured strip beam projection image is as follows: acquiring a lath width value A and a thickness B of a metal film sample in a projection image of the lath for the first time, According