Ultrasonic method and device for testing macroscopic cleanness of continuous casting billet

Abstract

A ultrasonic detection method of macrocleanness on continuous casting billet includes using multiple resolution analysis means to carry out analysis on original ultrasonic echo signal series at different frequency scope and carrying out treatment on analysis said echo signal with reasonable time frequency analysis, reconfigurating treated signal to generate signal with the same length as said echo signal series, comparing treated signal with defect judgment standard used at production unit to form planar distribution drawing of slag as per sample surface distribution.

Description

technical field [0001] The invention belongs to the field of non-destructive testing (NDT) of metallurgical materials, and relates to a method for inspecting inclusions (slag) inside a continuous casting slab by using ultrasonic waves. Background technique [0002] It is a common process to improve the comprehensive properties of steel through "ultra-purity, ultra-uniformity, and ultra-refinement", but there are many factors that will affect the purity of steel, such as slag coiling, continuous casting bias flow, and then affect the quality of steel. Inclusions (slag) are substances that directly affect the purity of steel and have a great impact on the properties of steel. It is very important to control the content of inclusions (slag). Generally speaking, the purity of steel mainly depends on the content of impurities in the steel, the size of the inclusions in the steel, the distribution of the inclusions, and the type of inclusions in the steel. There is no effective m...

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Problems solved by technology

[0004] It can be seen that although the metallographic method can check the inclusions in steel, it cannot meet the comprehensive and rapid inspection requirements for the detection of inclusions in steel (macro cleanliness), which is urgently needed in modern steel production. It is very incomplete, incomplete, and unrepresentative, and cannot detect the overall inclusions (macro cleanliness) of the steel

[0005] Ultrasonic has been used in the field of industrial testing for a long time, and it is widely used in various industries such as medical treatment, imaging, construction, electric power, etc. There are many related flaw detection standards for ultrasonic testing, but most of these standards and technologies are aimed at macroscopic flaw detection Applied, in recent years, driven by the electronics, information and other industries, ultrasonic testing is developing rapidly, but it is still a relatively new work in the application field of using ultrasonic testing to detect micro-sized defects

Especially in the aspect of using the non-destructive testing method to check the inclusion (slag) defects inside the steel, there is no published technology or patent

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