Testing Technology of Fire-Resistant Objects using Ultrasonic Low-Frequency Antenna Arrays

摘要

Fire-resistant blocks, on which the life of smelting furnace strongly depends are widely used in metallurgic industry. These fire-resistant blocks are produced by specialized industrial enterprises with production volumes of tens thousands items per year of different product types. To solve the problem of such items quality assurance the testing technology was made and special equipment for non-destructive testing of fire-resistant blocks was developed. Quality control is supposed to be held both at technological process and for ready-made products. The typical defects, reducing the lifetime of fire-resistant blocks, are cracks, holes, friability and foreign inclusions. Through-sounding method was chosen as the most suitable for defect detection, due to its sufficient reliability and productivity of testing. One of the important tasks during researches was to estimate the sensitivity of chosen method for testing fire-resistant block with the form of parallelepiped or more complex. Informative parameter was propagation velocity of longitudinal wave at through-sounding. The results of testing were screened as 2D color image. Researches showed the possibility of detection of stratifications with the diameter starting from 30 mm. Based on the results of the research the mobile system for technological testing of fire-resistant blocks was developed. In the paper the principle of operation and structure of the developed equipment are discussed as well as presented results of trials on physical models and on real samples, received during the operation testing. The developed system can be effectively implemented both for flaw detection of fire-resistant blocks and of other objects.