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Corrosive liquid and corrosion method for metallographic structure sample preparation of ferrite and austenite dissimilar steel welded joint

A technology of welded joints and metallographic structure, applied in the field of metallographic corrosion, can solve the problems of complex corrosion method, difficult over-corrosion of dissimilar steel joints, and metallographic structure display of ferrite and austenitic dissimilar steel welded joints, etc. To achieve the effect of not easy to excessive corrosion phenomenon, easy operation control, simple operation

Pending Publication Date: 2022-04-26
SHANGHAI UNIVERSITY OF ELECTRIC POWER
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0009] The object of the present invention is to provide a kind of corrosive solution and corrosion method for the metallographic structure sample preparation of ferrite and austenitic dissimilar steel welded joints, to overcome the complicated corrosion method of dissimilar steel joints in the prior art. The corrosive liquid is easy to over-corrode the joints of dissimilar steels or it is difficult to quickly and clearly display the metallographic structure of the welded joints of ferrite and austenitic dissimilar steels.

Method used

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  • Corrosive liquid and corrosion method for metallographic structure sample preparation of ferrite and austenite dissimilar steel welded joint
  • Corrosive liquid and corrosion method for metallographic structure sample preparation of ferrite and austenite dissimilar steel welded joint
  • Corrosive liquid and corrosion method for metallographic structure sample preparation of ferrite and austenite dissimilar steel welded joint

Examples

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Effect test

Embodiment 1

[0043] This embodiment provides a corrosion solution for preparing metallographic samples of welded joints of ferritic and austenitic dissimilar steels and its preparation method and application, wherein the ferritic steel is T91 steel and the austenitic steel is TP347H stainless steel, the specific operation steps are as follows:

[0044] (1) Sampling: Samples were taken at the welded joints of T91 / TP347H dissimilar steel.

[0045] (2) Pretreatment: The sample is completely soaked in absolute ethanol solution, placed in an ultrasonic cleaner for ultrasonic cleaning, and the surface is rinsed with water after the ultrasonic wave; After the sample is rinsed with deionized water, the grinding and polishing surface is placed on metallographic sandpaper of 400 mesh, 600 mesh, 800 mesh, and 1200 mesh in turn for fine grinding; finally, the ground test sample is washed and put on the polishing machine Polish until the observation surface of the sample reaches a mirror effect.

[0...

Embodiment 2

[0054] Compared with Example 1, most of them are the same, except that in this example, the electrolysis of 45 seconds in step (4) is changed to 30 seconds of electrolysis.

Embodiment 3

[0056] Compared with Example 1, most of them are the same, except that in this example, the electrolysis of 45 seconds in step (4) is changed to electrolysis of 60 seconds.

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Abstract

The invention relates to a corrosion liquid and corrosion method for ferrite and austenite dissimilar steel welded joint metallographic structure sample preparation, the corrosion liquid comprises an electrolytic corrosion liquid and an electrolytic polishing solution, the electrolytic corrosion liquid comprises picric acid, sodium dodecyl benzene sulfonate and concentrated hydrochloric acid, the ratio of the picric acid to the sodium dodecyl benzene sulfonate to the concentrated hydrochloric acid is 20 g: 8 g: (80-100) ml, and the electrolytic polishing solution is a mixture of the picric acid, the sodium dodecyl benzene sulfonate and the concentrated hydrochloric acid. The electrolytic polishing solution comprises alcohol, perchloric acid and glycerol, and the volume ratio of the alcohol to the perchloric acid to the glycerol is 150ml: 50ml: 25ml. The corrosive liquid can be used for metallographic structure sample preparation of a ferrite and austenite dissimilar steel welded joint, firstly, a ferrite and austenite dissimilar steel welded joint sample is pretreated, then the corrosive liquid is used for electrolytic corrosion polishing treatment, and a metallographic structure sample is obtained. Compared with the prior art, the corrosive liquid has the advantages that the phenomenon of excessive corrosion is not easy to occur, and the metallographic structure of the dissimilar steel welded joint can be quickly and clearly displayed; the corrosion method is simple to operate.

Description

technical field [0001] The invention belongs to the technical field of metallographic corrosion, and relates to a corrosion solution and a corrosion method for preparing metallographic samples of welded joints of ferrite and austenite dissimilar steels. Background technique [0002] Thermal power generation, especially coal-fired power generation, is the power generation form with the best comprehensive economy and the highest technological maturity at present, and the super (super) critical unit with the characteristics of high efficiency, energy saving and environmental protection can further reduce energy consumption and improve efficiency ,Improve the environment. In an ultra (super) critical unit, the steam temperature in each area of ​​the boiler superheater and reheater is different, and the requirements for the corrosion resistance, oxidation resistance and high temperature creep performance of the pipes used are also different. Depending on the steam parameters in ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C25F3/06C25F3/24
CPCC25F3/06C25F3/24
Inventor 李锦华纪冬梅金震杰高巍张世龙
Owner SHANGHAI UNIVERSITY OF ELECTRIC POWER