Corrosion method for original austenite grain size of tempered troostite and martensite structures

A technique of tempering troostite and prior austenite, which is applied in the field of prior austenite grain size testing, can solve problems such as inaccurate results of grain size, and achieve the goal of avoiding inaccurate results, accurate ratings, and clear grain boundaries Effect

Active Publication Date: 2021-07-02
ZHEJIANG MEILI HIGH TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] In order to overcome the problem of inaccurate results of the grain size tested by the oxidation method, the present invention provides a method for corrosion of the grain size of prior austenite in tempered troostite and martensite structure, the grain boundary of the sample corrosion is relatively clear, It can directly test the grain size of prior austenite in tempered martensite and tempered troostite, and the rating is accurate

Method used

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  • Corrosion method for original austenite grain size of tempered troostite and martensite structures
  • Corrosion method for original austenite grain size of tempered troostite and martensite structures
  • Corrosion method for original austenite grain size of tempered troostite and martensite structures

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Embodiment 1

[0023] The corrosion method of the original austenite grain size of tempered troostite and martensite structure, taking the original austenite of tempered troostite or martensite structure as the sample, pretreatment first, and holding at 500°C for 4h After that, quickly cool it in water, then grind and polish it, then clamp the sample with tweezers, completely immerse it in the corrosion solution and stir it constantly, etch for 5 minutes, and wait until the surface turns black, take out the sample, rinse it quickly with running water, and soak it with absolute ethanol Wipe the surface with a cotton ball, dry it with a hair dryer, then observe the grain size of the sample under a metallographic microscope, and get figure 1 The austenite grain boundary diagram shown.

[0024] The preparation method of described corrosive agent is: 1) 1000mL water and 50g picric acid are boiled together, get picric acid aqueous solution after removing sundry with filter paper; 2) 500mL water is...

Embodiment 2

[0029] The corrosion method of the original austenite grain size of tempered troostite and martensite structure, the original austenite of tempered troostite or martensite structure is used as the sample, firstly pretreated, and kept at 450°C for 6h After that, quickly cool it in water, then grind and polish it, then clamp the sample with tweezers, completely immerse it in the corrosive solution and stir it continuously, etch for 8 minutes. Wipe off the reactants on the surface of the sample with absorbent cotton, dry it with a hair dryer, and then observe the grain size of the sample under a metallographic microscope.

[0030] The preparation method of described corrosive agent is: 1) 1000mL water and 50g picric acid are boiled together, get picric acid aqueous solution after removing sundry with filter paper; 2) 500mL water is boiled together with 50g sodium dodecylbenzene sulfonate, obtain Sodium dodecylbenzenesulfonate aqueous solution; 3) 500mL water and 50g ferric chlori...

Embodiment 3

[0032] The corrosion method of the original austenite grain size of tempered troostite and martensite structure, taking the original austenite of tempered troostite or martensite structure as the sample, pretreatment first, and holding at 550°C for 3h Finally, quickly water-cooled, then polished and polished, then immersed in the primary treatment solution for 0.5h, and finally clamped the sample with tweezers, completely immersed in the corrosion solution and stirred continuously, after 15 minutes of erosion, the surface turned black, took out the sample, and quickly Rinse with running water, wipe off the reactants on the surface of the sample with absorbent cotton dipped in absolute ethanol, blow dry with a hair dryer, and then observe the grain size of the sample under a metallographic microscope.

[0033]The preparation method of described corrosive agent is: 1) 1000mL water and 50g picric acid are boiled together, get picric acid aqueous solution after removing sundry with...

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Abstract

The invention belongs to the technical field of original austenite grain size testing, and provides a corrosion method for the original austenite grain size of tempered troostite and martensite structures and aims at the problem that a grain size result tested by an oxidation method is not accurate. The corrosion method comprises the following operation steps that: the original austenite of the tempered troostite or martensite structures is taken as a sample, grinding and polishing treatment is carried out on the sample after the sample is pretreated, the sample is put into a corrosive agent to be corroded, and after the surface of the sample becomes black, the sample is cleaned with absolute ethyl alcohol and blow-dried, and the corrosive agent is composed of a saturated picric acid aqueous solution, sodium dodecyl benzene sulfonate and a saturated ferric trichloride aqueous solution. By utilizing the corrosion method, the corroded grain boundary of the sample is clear, the original austenite grain size of the tempered martensite and tempered troostite structures can be directly tested, and rating is accurate.

Description

technical field [0001] The invention relates to the technical field of testing the grain size of prior austenite, in particular to a method for corrosion of the grain size of prior austenite in tempered troostite and martensite. Background technique [0002] During the heat treatment process, the size of prior austenite grains directly affects the mechanical properties of the material. Fine austenite grains have high strength and toughness; coarse austenite grains have low strength, poor plasticity, and increased brittleness, and the manufactured parts are prone to accidents such as fracture and early failure during use; and coarse grains It is easy to deform and crack during the quenching process, so it is of great significance to accurately display the prior austenite grains of the material. [0003] There are many ways to characterize the grain boundaries of prior austenite. For example, Chinese patent CN109916787A discloses a method for measuring the austenite grain siz...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01N15/02G01N1/28G01N1/32
CPCG01N15/0227G01N1/28G01N1/32
Inventor 冯杰
Owner ZHEJIANG MEILI HIGH TECH
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