Method of acquiring metal surface oxide layer thickness

Abstract

The invention discloses a method of acquiring a metal surface oxide layer thickness. A pressure head is pressed into metal to be tested by using preset pressure in a constant force mode, and the speedof the pressure head is simultaneously and continuously recorded. When a changing value of the speed of the pressure head in preset time is greater than a preset speed value, the pressure head is indicated to be located at a boundary position of an oxide layer and a metal matrix and at this time, the pressure head stops moving. The time from contact starting of the pressure head and the metal tobe tested to pressure head moving stopping is set to be t1, the preset time is set to be t2, and according to the t1, the t2 and the recorded speed, the surface oxide layer thickness h of the metal tobe tested is calculated. By using the method of acquiring the metal surface oxide layer thickness, the pressure head only needs to be pressed into the metal to be tested in the constant force mode; the method is simple and is convenient to operate; steps of sample preparation, corrosion, observation through a microscope and the like are not needed; the method is labor-saving and time-saving; andmeasurement cost is low.

Description

technical field [0001] The invention relates to the technical field of metal quality detection, in particular to a method for obtaining the thickness of an oxide layer on a metal surface. Background technique [0002] When low-carbon steel is heated to 575-1370°C in air, an oxide layer will be formed on the surface due to high-temperature oxidation. The oxide layer thickness and composition depend on the duration and temperature of heating. Generally, the inner layer of the oxide layer is dark brown FeO. FeO is a clean structure with loose vias, and the interconnection between the grains is weak and easily damaged. The middle layer of the oxide layer is Fe 3 o 4 , Fe 3 o 4 It is relatively dense, without pores and cracks, and will form a peeling fracture. The outermost layer is Fe 2 o 3 , Fe 2 o 3 The structure is dense and is a spinel structure. Generally, the oxide layer is dominated by FeO, and Fe 2 o 3 The content is the least. The content of each layer in ...

AI Technical Summary

Problems solved by technology

Metallographic detection is more complicated, and it takes a long time to go through steps such as sample preparation, corrosion, and observation with a microscope, and the price of the microscope is also relatively high.

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