Quenched steel machining white layer detection method based on electrochemical detection device

Abstract

The invention discloses a quenched steel machining white layer detection method based on an electrochemical detection device. The method includes the steps: (1) selecting quenched steel to be detected and manufacturing the electrochemical detection device; (2) measuring an alternating current impedance spectrum of the quenched steel to be detected to obtain a charge transfer resistance value; (3) judging whether the surface layer of the quenched steel to be detected exists a white-layer tissue or not: (3.1) presetting a characterization value range of the quenched steel to be detected for machining a white layer; (3.2) determining that the surface layer of the quenched steel to be detected is provided with the white-layer tissue if the charge transfer resistance value obtained in the step (2) is within the characterization value range of the white layer, and determining that the surface layer of the quenched steel to be detected is not provided with the white-layer tissue if the charge transfer resistance value obtained in the step (2) is not in the characterization value range of the white layer. The quenched steel machining white layer detection method solves the problem of difficult and accurate and lossless detection when the white layer is machined by the quenched steel to be detected and provides technical support for rapid, in-situ and undamaged detection of white layers of parts through the electrochemical detection device.

Description

technical field The invention belongs to the field of white layer detection in hardened steel processing, in particular to a method for detecting white layer in hardened steel processing based on an electrochemical detection device. Background technique During the processing of hardened steel, it is easy to form a layer of metamorphic layer with structure and performance different from that of the base material. After chemical erosion, it appears white under the optical microscope, which is called "white layer". The chemical composition of the white layer is the same as that of the matrix material, but the microstructure has changed significantly (mainly composed of aphanitic martensite with very fine grains and a small amount of retained austenite and carbide), making it special Physical and mechanical properties. The hardness of the white layer is higher than that of the base material, which is beneficial to improve the wear resistance of the parts, but the white layer i...

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Problems solved by technology

However, the white layer of hardened steel is relatively thin (usually a few microns), which is much smaller than the minimum detection depth of the Barkhausen noise method, and the appearance of the white layer is not only accompanied by changes in surface hardness and stress, but also by chemical elements, grains, and positions. The error density and other aspects change, which makes it difficult to use the Barkhausen noise method to detect the white layer. Ian S

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