A method for detecting internal defects of cemented carbide rolls

Abstract

The invention discloses a method for detecting internal defects of a cemented carbide roll, belonging to the technical field of ultrasonic flaw detection, comprising the following steps: 1) selecting a cemented carbide roll as a test sample, making a comparison test block, and ensuring the accuracy of the comparison test block and the test sample The material is the same; 2) Concentric circular arc defects are set inside the comparison test block, and a number of holes and cracks are produced on the comparison test block, and the comparison test block is used to perform ACG, TCG correction and sensitivity adjustment of the phased array ultrasonic detector ;3) After the calibration of the instrument is completed, flaw detection is carried out on the inner arc surface of the cemented carbide roll to determine the specific location of the crack and determine the grinding plan. The method for detecting internal defects of cemented carbide rolls described in the present invention can quickly perform ultrasonic detection on cemented carbide slotted rolls and ribbed rolls, and can detect equivalent holes with an internal diameter of 0.3 mm for grooved and ribbed rolls, and can accurately Determine the position of the defect with an accuracy of 0.2mm to determine the grinding plan to ensure the rolling efficiency and the quality of the rolled steel.

Description

technical field [0001] The invention belongs to the technical field of ultrasonic flaw detection, and relates to a detection method for internal defects of a cemented carbide roll. Background technique [0002] Due to its high hardness, high strength, heat resistance, and corrosion resistance, the tonnage of cemented carbide rolls is 10 to 20 times that of cast iron, and conventional ductile iron roll materials will not be able to withstand greater rolling force And transmit greater torque, so cemented carbide rolls are widely used in steel rolling instead of cast iron rolls. [0003] With the increasingly fierce competition in the quality and price markets of steel products, iron and steel companies are constantly updating their own equipment and technology to continuously increase the rolling speed of the rolling mill; at the same time, reducing the number of shutdowns of the rolling mill and further improving the effective operation rate of the rolling mill. This has hig...

AI Technical Summary

Problems solved by technology

It is difficult to judge the specific location of the defect by routine inspection, so it often causes great adverse consequences, such as: some cracks have extended to the inside of the roll, which cannot be used anymore, and grinding is not necessary; if the cracks are not repaired, especially There are cracks in the grooves and ribs of the ribbed roll, and the depth of the cracks is not the same, and it is impossible to grind the cracks. These cracks continue to expand during the rolling process, causing the roll to crack; these consequences seriously affect the quality of the steel and rolling. production efficiency, resulting in increased rolling costs or unnecessary waste

However, there is no ultrasonic testing method or related reports for cemented carbide slotted rolls and ribbed rolls so far, so it is of great significance to develop a detection method for internal defects of cemented carbide slotted rolls and ribbed rolls.

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