Steel austenite grain size etchant and preparation method and application thereof

Abstract

The invention provides a steel austenite grain size etchant and a preparation method and application thereof, the steel austenite grain size etchant comprises a carboxyl compound, a surfactant and a diluent, and the carboxyl compound is one of p-acetic acid or oxalic acid; the surfactant is any one of lauryl sodium sulfate, sodium dodecyl benzene sulfonate or dishwashing liquid; and the diluent is a mixed solution of water and ethanol. When the etchant is used for etching a steel material, a high-temperature oxidation treatment process is not needed, a direct hardening method is adopted, a grain boundary is directly and chemically etched, the operation is simple and easy to master, error detection is not prone to occurring, and time and cost can be saved. The etchant provided by the invention can clearly display grain boundaries of wheel steel, carbon structural steel and low-medium carbon alloy steel sample grains, the grain size is clear and complete under 100 times, the grain size is easy to grade, and the effect is good. In addition, the problems that in the prior art, picric acid reagents pollute the environment and affect public safety can be solved.

Description

technical field [0001] The invention relates to the application field of etchant, in particular to a steel austenite grain size etchant and its preparation method and application. Background technique [0002] The austenite grain size of steel has a great influence on mechanical, physical properties, chemical properties and heat treatment. Therefore, the evaluation of austenite grain size is very important for judging the quality of steel and checking the correctness of thermal processing technology. etc. are of great significance. [0003] The display of austenite grain size of iron and steel materials generally adopts direct hardening method, oxidation method, and corrosion by reagents such as saturated picric acid, picric acid and sodium dodecylbenzenesulfonate mixed solution. However, when the above method is used to etch the grain boundary, on the one hand, picric acid has been listed as an environmental pollutant and its use is restricted in large quantities because o...

AI Technical Summary

Problems solved by technology

However, when the above method is used to etch the grain boundary, on the one hand, picric acid has been listed as an environmental pollutant and its use is restricted in large quantities because of its explosiveness, flammability, and toxicity, so as to avoid polluting the environment and affecting public safety; On the other hand, the oxidation method requires the use of a heat treatment furnace to perform high-temperature oxidation treatment on the sample. The high-temperature oxidation treatment process and the subsequent sample preparation process are complex, requiring high levels of inspection personnel, difficult to master, easy to make mistakes, and waste time and cost.

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