Method for detecting distribution and content of residual austenite in low alloy structure steel

Abstract

The invention discloses a method for detecting distribution and the content of residual austenite in low alloy structure steel. Water is used as cooling liquid, metallographic waterproof abrasive paper is used for rough grinding and fine grinding of a test surface of a sample, the sample subjected to fine grinding is polished, sodium metabisulfite, picric acid, sodium hydroxide, distilled water, hydrochloric acid and absolute ethyl alcohol are mixed, stirred and heated to prepare a corrosion reagent, the polished sample is subjected to electrolytic polishing treatment, the sample subjected toelectrolytic polishing treatment is placed into prepared corrosion solvents to remove interference phases, and distribution and the content of the residual austenite of the sample are detected by metallographic observation and representation. The method is simple in operation and short in polishing corrosion time. After the low alloy structure steel is corroded, a residual austenite structure in the low alloy structure steel can be clearly displayed. Characteristic parameters such as the content, the size, the shape and distribution of the residual austenite can be rapidly, accurately and quantitatively analyzed by metallographic software.

Description

Technical field [0001] The invention belongs to the technical field of metallographic structure display and quantification, and specifically relates to a method for detecting the distribution and content of retained austenite in low alloy structural steel. Background technique [0002] The strength and toughness of steel is closely related to its microstructure. Characteristic parameters such as the content, size, shape and distribution of retained austenite have an important effect on the strength and toughness of low-alloy structural steels. Therefore, the quantitative analysis of the distribution and content of retained austenite is of great significance to the structural design of low-alloy structural steels and the improvement of material properties, and has become an indispensable testing item in low-alloy structural steels. [0003] At present, the analysis methods commonly used in laboratories include X-ray diffraction technology and EBSD analysis technology. When using X-...

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Problems solved by technology

[0003] At present, the commonly used analysis methods in the laboratory include X-ray diffraction technology and EBSD analysis technology. When using X-ray diffraction technology to analyze the residual austenite content, it is necessary to make a standard sample. The process is complicated, and it cannot reflect the residual austenite in low-alloy structural steel. Distribution characteristics

Although the distribution of retained austenite in low-alloy structural steel can be displayed using EBSD technology, the sample preparation process is complicated, the cost is high, the test period is long, and the display effect is greatly affected by the internal stress of the sample.

[0004] Some existing metallographic display technologies are mainly for corrosion of M / A island, which has many interference phases, and mainly for pipeline steel

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