A kind of high-alloy austenitic stainless steel microstructure and σ mesophase color etchant and corrosion method

Abstract

The invention provides a high-alloy austenitic stainless steel microscopic structure, a sigma intermediate-phase color corrosive agent and a corrosion method. The high-alloy austenitic stainless steel microscopic structure, the sigma intermediate-phase color corrosive agent and the corrosion method have the advantages of being good in corrosion effect, good in display effect, free of pollution and stable in corrosion reaction. The corrosion method includes the steps of uniformly stirring raw materials by using a glass rod, allowing the raw materials to stand for 15-30 minutes, and preparing the corrosive agent, wherein the corrosive agent comprises the flowing components: 0.1-2g of potassium permanganate, 5-25ml of hydrochloric acid with the mass percentage concentration being 35%, 5-30ml of nitric acid with the mass percentage concentration being 68%, 0.1-1.2g of copper sulfate and 150-300ml of deionized water; and carrying out coarse grinding, fine grinding and polishing on a sample, washing the sample with absolute ethyl alcohol, then carrying out blow-drying, soaking the sample to be tested in the corrosive agent for corrosion for 15-300 seconds, placing the corrosion surface of the sample upwards until the metallographic-phase surface of the sample is corroded to be yellow, washing the obtained rough corrosion test sample under a water faucet, cleaning the obtained rough corrosion test sample with 95% alcohol after washing, and then carrying out blow-drying by using cold air to complete metallographic-phase corrosion of the stainless steel structure.

Description

technical field [0001] The invention relates to a high-alloy austenitic stainless steel microstructure and σ mesophase color etchant and a corrosion method. Background technique [0002] Since the advent of high-alloy stainless steel, due to the performance advantages of high-alloy stainless steel (36-55% alloy content), it has excellent corrosion resistance, mechanical properties, and welding properties. The combination of these excellent properties makes it widely used in petroleum, chemical industry, electric power, marine and other fields. Generally, the precipitation temperature range of the σ phase of austenitic stainless steel is 600-1000°C. As the degree of alloying increases, the precipitation temperature range moves to the high temperature direction. In addition, due to poor high-heat processing performance, edge cracking occurs during hot processing, and the thermal processing performance has a certain relationship with the intermediate precipitated phase (mainly...

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Problems solved by technology

In addition, due to poor high-heat processing performance, edge cracking occurs during hot processing, and the thermal processing performance has a certain relationship with the intermediate precipitated phase (mainly σ phase), so it needs to be observed and studied. Currently, solutions such as 35% ferric chloride etc. are used to electrolytically corrode the structure of high stainless steel, but because samples at different temperatures need to use different voltages, currents, structures and are prone to over-corrosion, the σ phase is easily corroded, and the operation is more troublesome

[0003] The applicant has an invention patent with the patent number 201210189207.9, which relates to a duplex stainless steel microstructure and σ mesophase color etchant and corrosion method, suitable for the detection of duplex stainless steel, but not suitable for high-alloy stainless steel, when used For high-alloy stainless steel, the erosion effect is not good, and the corrosion effect of the sample structure is poor

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