Rapid detection method and rapid detection device of non-metallic inclusions in metal

Abstract

The invention discloses a rapid detection method of non-metallic inclusions in metal. The rapid detection method comprises the following five steps of: heating and smelting a metal test sample, separating the inclusions, detecting the total amounts and the sizes of the inclusions, condensing metal liquid, and detecting the three-dimensional shape and components of the inclusions. The invention further provides a special rapid detection device comprising a heating furnace device, a metal liquid rotation device, a video collection device and an image analysis system. The metal test sample is rapidly smelted and the steel liquid is driven to rotate; centrifugal force and gravity are used for rapidly upwards floating various non-metallic inclusions in the metal liquid and gathering the various non-metallic inclusions at the center of the surface of the metal liquid; high speed photography and video analysis software is used for rapidly obtaining the total amount and the size distribution of the non-metallic inclusions in the metal test sample; the metal liquid is rapidly cooled and condensed and the inclusions are cured on the surface of the metal test sample; and a scanning electron microscope and the energy spectrum analysis are used for obtaining the three-dimensional shapes and the components of the non-metallic inclusions in the metal test sample. According to the rapid detection method and the device disclosed by the invention, the direction is rapid and convenient, the analysis is accurate and visual, and cleaning and no pollution can be realized.

Description

technical field [0001] The invention relates to a rapid detection method and device for inclusions, which can quickly detect the total amount, size distribution and composition of non-metallic inclusions in steel, and belongs to the technical field of metallurgy. Background technique [0002] The presence of inclusions has great harm to the properties of steel. The physical and mechanical properties of the inclusions and the base metal, such as elasticity, plasticity and thermal expansion coefficient, are quite different. During the stress process, the inclusions cannot deform with the metal. The metal with large deformation will produce plastic flow around the inclusion with small deformation. The stress distribution at the junction of the two is uneven, and stress concentration occurs, leading to the generation of microcracks, providing a source of material damage and accelerating the process of plastic fracture. As a result, the ductility, toughness and fatigue strength...

AI Technical Summary

Problems solved by technology

Macroscopic methods include X-ray detection, magnetic particle inspection, ultrasonic detection and sulfur printing method, etc. The disadvantage of these methods is that the resolution is too low, and generally only large non-metallic inclusions over 1mm can be detected

Microscopic methods include metallographic method, rating method, large sample electrolysis method, acid solution method, etc. The disadvantages of these methods are that the metallographic method takes a long time and can only detect inclusions on the surface of steel samples, even if quantitative metallographic methods are used. The total amount of inclusions in the volume steel, and the metallographic method still has the deficiency of false reporting of particle size, and the metallographic grinding method cannot guarantee that the maximum radius plane of the inclusions is exactly ground, so the particle size of the inclusions observed under the metallographic microscope is not accurate. It must be the true particle size of the inclusion; the rating method is based on the metallographic method, which is artificially rated, and there is a large subjective error; the large sample electrolysis method often takes several days to half a month, and can only detect particles with a diameter greater than 50 Micron non-metallic inclusions, there is still a lot of human error in the screening of anode slime

In addition, the electrolysis of aqueous solution also has the problem of some inclusions being dissolved in the electrolyte to cause errors; the acid solution method also has the shortcomings of the electrolysis method.

However, the detection methods successfully applied to non-metallic inclusions in aluminum, such as filtration method and current pulse method, cannot be adopted due to the high melting point of molten steel and other reasons.

The total oxygen analysis method can reflect the total amount of inclusions in steel to a certain extent, but it is limited to oxidized inclusions in steel, and the size distribution of inclusions cannot be obtained.

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