Metallographic corrosive agent for advanced high-strength steel residual austenite dyeing and using method of metallographic corrosive agent

Abstract

The invention discloses a metallographic corrosive agent for advanced high-strength steel residual austenite dyeing. The metallographic corrosive agent is prepared from an alcoholic solution and a surfactant; the alcoholic solution is prepared from the components in percentage by mass: 3.5-15% of sulfuric acid, 12-15% of hydrochloric acid, 7-10% of FeCl3, and the balance of anhydrous alcohol. In addition, the invention discloses a using method of the metallographic corrosive agent. The method includes the steps that a polished metallographic sample is immersed in the metallographic corrosive agent for a period of time, then the surface of the metallographic sample is cleaned and blow-dried, and the metallographic sample is observed on a color microscope. The metallographic corrosive agentis good in stability and simple in formula, in practical application, various structures of steel are corroded by the metallographic corrosive agent to achieve sufficient contrast and the structures are effectively distinguished, and especially when advanced high-strength steel is subjected to metallographic corrosion by the metallographic corrosive agent, the structures of bainite, martensite, ferrite and residual austenite in the metallographic structure are all displayed, and different colors are presented.

Description

technical field [0001] The invention relates to a corrosive agent and a using method thereof, in particular to a corrosive agent suitable for steel types and a using method thereof. Background technique [0002] Advanced high-strength steel is mainly strengthened by phase transformation, so its structure is relatively complex. The structure of advanced high-strength steel contains martensite, ferrite, bainite and / or retained austenite, and the main steel series include dual phase steel (DP), twinning induced plasticity (TRIP) steel, multiphase steel ( CP), Quenched Partition Steel (QP Steel) and Martensitic Grade Steel (Mart), etc. Advanced high-strength steel (AHSS) for automobiles is divided into hot-rolled, cold-rolled and hot-dip galvanized products, and their process characteristics are all strengthened through phase transformation. The tensile strength of advanced high-strength steel can be as high as 1000MPa or more. In order to achieve high strength, more alloying ...

AI Technical Summary

Problems solved by technology

However, there are two problems with this color metallographic method. One is that the etchant is not stable enough. Even if the corrosion time is precisely controlled, the structure cannot be effectively corroded in many cases; the other is that the residual austenite and martensite The difference in contrast is still relatively small, and in many cases it cannot be effectively distinguished

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