Method for detecting surface oxidized scale sample of hot rolled steel plate

Abstract

The invention provides a method for detecting a surface oxidized scale sample of a hot rolled steel plate, aims to overcome the defects of a conventional test sample preparation method and checking method of hot rolled metal oxidized scale, and belongs to the field of back scattering image analysis of a surface layer structure of a high-temperature oxidized metal. The method specifically comprises the following steps: putting a metal sample which is oxidized at high temperature into a non-metal tube, performing cold embedding by using liquid epoxy resin and a curing agent of the liquid epoxy resin, and implementing processes such as grinding, polishing, corrosion by using a nitric acid ethanol mixed solution and surface carbon plating, so as to finally obtain a metal cross section oxidized scale sample which is applicable to observation by using a field emission electronic probe. Due to the adoption of the method, the oxidized scale sample of which metal is subjected to high-temperature oxidization is relatively easily and conveniently prepared, the loose phase of Fe2O3, Fe3O4 and FeO on an outer layer can be effectively protected by the epoxy resin in a cold state, and the surface oxidized scale can be prevented from dropping off in hot embedding. Through corrosion by using a mixed solution of nitric acid and ethanol, the structure of the surface oxidized scale and the metallographic phase of a metal substrate can be clearly revealed after corrosion, and the imaging effect can be relatively clear.

Description

technical field [0001] The invention belongs to the field of backscattering image analysis of the surface structure of metal high-temperature oxidation, and in particular relates to a detection method for a sample of iron scale on the surface of a hot-rolled steel plate. Background technique [0002] At present, as more and more hot-rolled products are gradually replacing cold-rolled products of the same specification, users have higher and higher requirements for the surface quality of hot-rolled strip steel. In recent years, although my country's iron and steel enterprises have gradually paid attention to the surface quality of hot-rolled products, surface defects also appear frequently, resulting in the reduction of the surface and internal quality of steel products, causing the subsequent deep processing scrap rate to seriously exceed the standard, and the surface finish of the rolled slab is extremely poor. Therefore, in order to enhance the competitiveness of hot-rolle...

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Problems solved by technology

[0003] At present, the sample preparation method of hot-rolled metal oxide scale mainly adopts hot-mounting, as shown in the patent CN-101856669-A, the disadvantage of hot-mounting is that it needs to be heated at 50-130°C and formed at 80-300bar during the heating process. Loading force, the iron oxide scale sample produces partial stress during the hot mounting process, and the iron oxide scale is easily broken and tilted, which creates great difficulties for the detection of iron oxide scale

Secondly, the current corrosive solution is a mixed solution of hydrochloric acid and ethanol. Its disadvantage is that it can only corrode the iron oxide scale structure but cannot corrode the metal matrix structure, which is not conducive to the detection of the iron oxide scale matrix.

At present, the metallographic microscope is mainly used in the detection equipment of iron oxide scale. Its shortcoming is that the imaging effect of light microscope is not clear, and it cannot meet the detection requirements for the precise structure and thickness of iron oxide scale.

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