Metallographic corrosion method for simultaneously displaying austenitic stainless steel and aluminide coating organization structure on surface of austenitic stainless steel

Abstract

The invention provides a metallographic corrosion method for simultaneously displaying austenitic stainless steel and an aluminide coating tissue structure on the surface of the austenitic stainless steel. The method comprises the following steps: mixing 40-55% of hydrochloric acid, 37-48% of ultrapure water and 8-12% of glycerol in percentage by volume to obtain a liquid phase, and then adding copper sulfate and ferric trichloride to obtain a metallographic corrosive agent; uniformly dripping the prepared metallographic corrosive agent on the surface of the coating sample to corrode for 15-25seconds; after the surface gradually loses the finish degree, immediately using a large amount of ultrapure water for washing, finally, sucking absolute ethyl alcohol or acetone to clean residual water spots and impurities on the surface of the sample, using a blower used for blow-drying so that the austenite steel and the organization structure of the aluminide coating on the surface of the austenite steel can be developed at the same time. The corrosion method is mainly used for simultaneously developing organizational structures of the austenitic stainless steel and the aluminide coating on the surface of the austenitic stainless steel, and has a remarkable effect of simultaneously developing a matrix and a coating structure in an original state and a service state.

Description

technical field [0001] The invention belongs to the technical field of metallographic inspection of metal materials, in particular to a metallographic corrosion method for simultaneously displaying the microstructure of austenitic stainless steel and its surface aluminide coating. Background technique [0002] Austenitic stainless steel is widely used in the selection of high-temperature components of boilers for ultra-supercritical (USC) thermal power units in service and advanced ultra-supercritical (A-USC) units in the near future due to their excellent high-temperature mechanical properties and competitive cost. among. With the continuous improvement of steam parameters of thermal power units, the problem of high-temperature oxidation on the steam side of austenitic steel boiler tubes has gradually become prominent, and the resulting oxide scales have fallen off, leading to tube burst accidents. The surface preparation of aluminide coating is one of the protection techn...

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Problems solved by technology

[0006] The purpose of the present invention is to provide a metallographic corrosion method for simultaneously corroding the austenitic metallographic structure and the structure of the aluminide coating, so as to solve the problem that the existing metallographic etchant cannot complete the metallographic imaging of the austenitic steel substrate and the coating at the same time Corrosion problems

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