An etchant for displaying prior austenite grain boundaries in low-alloy wear-resistant steel and its application

Abstract

The invention relates to the application field of etchant, in particular to an etchant for displaying the original austenite grain boundary of low-alloy wear-resistant steel and its application. The etchant of the invention uses picric acid and dodecylbenzenesulfonic acid Sodium, tableware detergent, distilled water, potassium thiocyanate, and bromine water can be heated to 70 degrees Celsius. When applying, the metallographic sample should be made first, and the metallographic sample should be coarsely ground, finely ground, and polished. After the etchant was corroded for 40s, the original austenite grain boundaries were observed by scanning electron microscopy. The etchant of the invention has a simple preparation method, and the application operation is simple, safe and fast.

Description

technical field [0001] The invention relates to the application field of etchant, in particular to an etchant for displaying the original austenite grain boundary of low-alloy wear-resistant steel and its application. Background technique [0002] Grain size is a measure of grain size, which directly affects the mechanical and process properties of metal materials. Metal wear-resistant materials are widely used in industry. Low-alloy wear-resistant steel has attracted extensive attention from relevant researchers at home and abroad because of its high hardness and good impact properties. Therefore, it shows that the original grain boundary of low-alloy wear-resistant steel has important meaning. Whether the original austenite grain boundary can be clearly displayed depends on many factors, such as the chemical composition, structure, heat treatment state, corrosion method, reagent and time of the sample. The structure is easy to display, but the grain boundary is difficult...

AI Technical Summary

Problems solved by technology

Chinese patent CN102507292A discloses "a method for displaying austenite grain boundaries in low-carbon micro-alloy steels". More than 70% hydrochloric acid, hydrofluoric acid and copper chloride with a concentration greater than 70%; the advantage is that the display agent solution has stable performance and good reproducibility, but the disadvantage is that it is cumbersome to apply to the solution and there are many kinds of solutions

Chinese patent CN105420731A discloses a "metallographic corrosion solution suitable for displaying quenched state grain boundaries of various types of steel workpieces and its preparation method", and the composition of the display agent includes picric acid, sodium dodecylbenzenesulfonate, Solutions such as sodium chloride, copper chloride and hydrochloric acid, which are specially used for carbon steel, low-medium alloy steel and bearing steel, are not suitable for the low-alloy wear-resistant steel of the present invention

Chinese patent CN101349621A discloses "a method for clearly displaying austenite grains in low-carbon and low-alloy steels". The sample erosion time is as long as 40-60min, and the efficiency is low

Wiederman et al. used boiling CrO3-NaOH etchant to etch low- and medium-alloy steels, and the effect was better; but the sample must be preheated to 120-130°C before immersing in the etchant, so the operation is inconvenient, and 120°C Temperature can adversely affect mounting materials

Many existing invention patents show that there are reagents such as picric acid and sodium dodecylbenzenesulfonate at the austenite grain boundary, which are all aimed at carbon steel, medium alloy steel or bearing steel, but for the low Alloy wear-resistant steel is not involved

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