Etching agent for displaying low alloy wear-resistant steel original austenite grain boundary and application of etching agent

Abstract

The invention relates to the field of etching agent application, in particular to an etching agent for displaying the low alloy wear-resistant steel original austenite grain boundary and application of the etching agent. The etching agent is prepared through the step that picric acid, sodium dodecyl benzene sulfonate, a tableware cleaner, distilled water, potassium thiocyanate and bromine water are heated to 70 DEG C; and when the etching agent is applied, a metallographic specimen is firstly prepared, the metallographic specimen is subject to coarse grinding, fine grinding and polishing to be etched through the prepared etching agent for 40 s, and the original austenite grain boundary of the specimen is observed through a scanning electron microscope. The etching agent is simple in manufacturing method, and application operation is easy, convenient, safe and rapid.

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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