Method for displaying and quantitatively determining retained austenite or island martensite- austenite in TRIP steel

A quantitative detection method and technology of retained austenite, applied in the preparation of test samples, material analysis by observing the influence of chemical indicators, and analysis by making materials undergo chemical reactions, etc., can solve the problem of display and quantitative detection There are no problems such as instructions, achieving the effect of high accuracy of quantitative results, easy identification, and improved accuracy

Inactive Publication Date: 2009-03-11
WUHAN IRON & STEEL (GROUP) CORP
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0009] The above patents introduce the manufacturing method of automobile sheet, TRIP steel or steel plate containing certain

Method used

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  • Method for displaying and quantitatively determining retained austenite or island martensite- austenite in TRIP steel
  • Method for displaying and quantitatively determining retained austenite or island martensite- austenite in TRIP steel
  • Method for displaying and quantitatively determining retained austenite or island martensite- austenite in TRIP steel

Examples

Experimental program
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Embodiment 1

[0035] A method for displaying and quantitatively detecting retained austenite or MA islands in TRIP steel, the steps of which are as follows:

[0036] (1) After the TRIP steel sample to be inspected was intercepted according to the sampling standard, it was hot-mounted with phenolic resin inserts to prepare a metallographic sample;

[0037] (2) After the metallographic sample is ground and polished, it is lightly etched with 1% (wt.) nitric acid alcohol solution for about 8 seconds, and then lightly polished, that is, on the flannelette polishing disc Lightly throw water for 2 seconds, then use 1% (wt.) sodium bisulfite (Sodium Metabisulfite, molecular formula Na 2 S 2 o 5 ) aqueous solution and 6% (wt.) picric acid alcohol solution are uniformly mixed at a volume ratio of 1:1 to make a corrosion solution, and the metallographic sample is put into the corrosion solution and etched for 55 seconds;

[0038] (3) observe the structure of TRIP steel under leica DM6000 M metallo...

Embodiment 2

[0049] A method for displaying and quantitatively detecting retained austenite or MA islands in TRIP steel, the steps of which are as follows:

[0050](1) After the TRIP steel sample to be inspected was intercepted according to the sampling standard, it was hot-mounted with phenolic resin inserts to prepare a metallographic sample;

[0051] (2) After the metallographic sample is ground and polished, it is lightly etched with 3% (wt.) nitric acid alcohol solution for 5 seconds, and then lightly polished, that is, on the flannelette polishing disc. Water is lightly thrown for 1 second, and then utilizes 3% (wt.) sodium metabisulfite (Sodium Metabisulfite, molecular formula Na 2 S 2 o 5 ) aqueous solution and 2% (wt.) picric acid alcohol solution in a volume ratio of 1:1 to prepare a corrosion solution, and put the metallographic sample into the corrosion solution and etch for 65 seconds;

[0052] (3) Observe the structure of TRIP steel under a metallographic microscope: ferri...

Embodiment 3

[0055] A method for displaying and quantitatively detecting retained austenite or MA islands in TRIP steel, the steps of which are as follows:

[0056] (1) After the TRIP steel sample to be inspected was intercepted according to the sampling standard, it was hot-mounted with phenolic resin inserts to prepare a metallographic sample;

[0057] (2) After the metallographic sample is ground and polished, it is lightly etched with 2% (wt.) nitric acid alcohol solution for 6 seconds, and then lightly polished, that is, on the flannelette polishing disc. The water is lightly thrown for 1.5 seconds, and then 2% (wt.) sodium bisulfite (Sodium Metabisulfite, molecular formula Na 2 S 2 o 5 ) aqueous solution and 4% (wt.) picric acid alcohol solution are uniformly mixed at a volume ratio of 1:1 to make an etching solution, and the metallographic sample is put into the etching solution and etched for 60 seconds;

[0058] (3) Observe the structure of TRIP steel under a metallographic mic...

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Abstract

The invention relates to a display and quantitative detection method of residual austenite or island martensite-austenite (MA island for short) in TRIP steel. The method comprises the steps: (1) a TRIP tapping sample is prepared into a metallographic specimen; (2) after grinding and polishing, the metallographic specimen is light etched for 5 to 8 seconds in Nital of 1 to 3 percent by weight, and water is sprinkled on a flannel polishing disk for 1 to 2 seconds; sodium pyrosulfite water solution of 1 to 3 percent by weight and picral of 2 to 6 percent by weight are mixed by volume ratio of 1:1 to prepare corrosive liquid, then the metallographic specimen is put into the corrosive liquid for etching of 55 to 65 seconds; (3) the structure of the TRIP steel is observed under a metallurgical microscopy: the delta ferrite is minus blue, the residual austenite or MA island is white, and bainite is brownish-black; and (4) each phase in the structure is carried out quantitative analysis. The method presents different colors, each phase of structure has distinct layers which are easy to distinguish; and a quantitative image analysis method is utilized to fix amount of the feature object structure, which is objective and accurate and has good repeatability.

Description

technical field [0001] The invention relates to a display and quantitative detection method of retained austenite or island martensite-austenite, especially the display and quantitative detection of retained austenite or island martensite-austenite in TRIP steel method. Background technique [0002] In recent years, the application of TRIP steel with high strength and high toughness in the automobile industry has been increasing year by year, and the market prospect is promising. The content, volume, shape, size, existence state and other factors of retained austenite (sometimes martensite-austenite, also known as MA island because of its island shape) in TRIP steel affect its structure and properties. Influence plays a key role. The difficulty in analyzing the microstructure of TRIP steel by quantitative metallographic techniques lies in the identification and extraction of characteristic microstructures. With the traditional corrosion method, only the grayscale image of...

Claims

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Application Information

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IPC IPC(8): G01N21/78G01N1/32
Inventor 刘继雄邱保文李平和陈士华张敏李建华邓照军孙宜强吴立新李立军
Owner WUHAN IRON & STEEL (GROUP) CORP
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