Method for detecting non-metallic inclusions in steel

Abstract

The invention discloses a method for detecting non-metallic inclusions in steel, which adopts the following process: carrying out solid solution strengthening on a sample to be detected to prepare a rod-shaped sample; taking a stainless steel sleeve as a cathode, taking a rod-shaped sample as an anode, and performing electrolytic extraction by adopting a semipermeable membrane for isolation, wherein the electrolyte comprises the following components in proportion: 0.01 g / ml-0. 1 g / ml of tetramethylammonium chloride, 0.1 ml / ml-0. 25 ml / ml of acetylacetone and the balance of a methanol solution with the mass fraction of 95%-99%; dissolving the electrolyzed electrolyte in absolute ethyl alcohol, and filtering by using a filter membrane; dissolving the inclusions on the filter membrane in the absolute ethyl alcohol solution again, and obtaining clean inclusions after magnetic separation and filtering; inlaying clean inclusions on a metal plane with a conductive adhesive, and spraying platinum to prepare an ASPEX observation sample; and detecting the ASPEX observation sample by using an ASPEX automatic scanning electron microscope to obtain detection information of all extracted inclusions. According to the method, the non-metallic inclusions in the steel can be nondestructively, completely and quickly detected, and the manual workload and errors caused by manual work are greatly reduced.

Description

technical field [0001] The invention belongs to the field of electrochemical and physical detection, in particular to a method for detecting non-metallic inclusions in steel. Background technique [0002] Many studies have shown that the type, size, distribution and quantity of non-metallic inclusions in steel have a great influence on the quality of steel. Non-metallic inclusions destroy the continuity of the steel matrix structure, can reduce the mechanical properties and fatigue properties of the steel, and deteriorate the cold and hot workability and some physical and chemical indicators of the steel. Accurate and complete characterization of non-metallic inclusions in steel is particularly important to improve the cleanliness of steel. [0003] The main disadvantages of the traditional detection method of non-metallic inclusions combined with electrochemical extraction and field emission scanning electron microscopy are: 1. The electrolyte uses acidic or alkaline solut...

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Problems solved by technology

[0003] The main disadvantages of the traditional detection method of non-metallic inclusions combined with electrochemical extraction and field emission scanning electron microscopy are: 1. The electrolyte uses acidic or alkaline solutions. During the electrolysis process, the electrolyte will dissolve part of the oxides. 2. Carbide is difficult to remove for electrolytic samples that have not undergone solid solution treatment; 3. Field emission scanning electron microscopy detects inclusions, the analysis speed is slow, the manual working measuring tool is large, and there are no inclusions in 99% of the field of view that need to be judged manually Inclusions, 100mm 2 The scanning time of the detection area is about 10 hours; 4. The analysis results are unreliable, the field emission electron microscope is a static scanning, the analysis is that the collected pictures are not the actual samples, and the inclusions and pollutants cannot be effectively distinguished

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