Medium-high carbon steel actual grain size developer and developing method

Abstract

The invention discloses a medium-high-carbon steel actual grain size developer, belonging to a reagent and a method used for microexamination of the metallographic structure of iron and steel materials, and particularly relates to a medium-high carbon steel metallographic structure micro detection reagent and a detection method. The developer is composed of the following components in terms of solution volume (ml) and mass (g): 50ml of saturated picric acid solution, 0.01-0.1g of picric acid, 10-30ml cleanser essence and 0.01-0.2g of ferric trichloride. The method comprises the following steps of sample preparation, developer preparation, sample dyeing, microscopic observation and electronic image acquisition. The medium-high carbon steel actual grain size developer provided by the invention has the advantages of novel component conception, stable solution performance, good repeatability, simple and reliable operational process and complete grain boundary display; the medium-high carbon steel actual grain size can be clearly recognized, and is ranked; and the display and detection of the actual grain size of the steel product are ranked, thus providing advantageous conditions for product safe application and product research and development, and obtaining remarkable economic benefits and social benefits.

Description

technical field [0001] The invention belongs to a reagent for microscopic inspection of metallographic structure of iron and steel materials, in particular to a reagent and method for microscopic detection of metallographic structure of medium-high carbon steel. Background technique [0002] The actual grain size of steel is the austenite grain size obtained under certain heat treatment or hot working conditions, and its actual grain size has a great influence on the mechanical properties and process properties of metal materials. Therefore, it is of great significance to detect the actual grain size of steel, especially in the factory inspection of train wheels and product development research. The carbon content of the wheel steel is 0.55-0.65%, which is a medium-high carbon steel, and the structure is pearlite + intermittent reticular ferrite. However, the display of the actual grain size has always been a difficult point, and saturated picric acid solution has been used...

AI Technical Summary

Problems solved by technology

The defect is that due to the lack of contrast on the surface of the metal sample, the grain boundary is not clearly displayed, and the inference can only be made based on the network trend of intermittent reticulated ferrite in the microstructure, and the specific level cannot be determined, and even misjudgment occurs; or The sample is subjected to another heat treatment to evaluate the austenite grain size, which delays the inspection time and inspection cost

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