A magnetic particle detection method for cracks based on temperature difference

Abstract

The invention belongs to the related technical field of non-destructive testing of ferromagnetic materials, and discloses a crack magnetic powder detection method based on temperature difference. The detection method comprises the following steps: first, in a magnetization field, spray the magnetic powder with a temperature difference from the tested piece to be sprayed On the tested piece, obtain the thermal image of the tested piece in real time; then, process the obtained thermal image to obtain the temperature change of the tested piece, and then perform crack identification on the tested piece according to the obtained temperature change result ; Among them, when there is a crack in the test piece, the leakage magnetic field generated at the crack will attract the magnetic powder to gather to form a magnetic mark, the temperature at the magnetic mark is different from the temperature in other areas of the test piece, and the temperature at the magnetic mark is different from that of the test piece. The difference between the test piece temperatures is magnified due to magnetic particle aggregation. The method avoids the information affecting the cracked magnetic marks when manually removing non-relevant magnetic marks, and uses ordinary dry magnetic powder, which is easy to remove and recycle, and has low pollution to the test piece and no pollution to the environment.

Description

technical field [0001] The invention belongs to the related technical field of non-destructive testing of ferromagnetic materials, and more particularly relates to a crack magnetic powder detection method based on temperature difference. Background technique [0002] With the needs of social production and development, the demand for ferromagnetic components in various industrial fields has increased significantly, and there is a higher and higher demand for their surface quality. Nondestructive testing mainly includes five methods: ultrasonic testing, ray testing, eddy current testing, magnetic particle testing and penetrant testing. Among them, magnetic particle testing is an important nondestructive testing technology with a large amount and a wide range. More than 70% of aviation, aerospace, military, Steel components in railway and petroleum industries, and more than 80% of automobile steel safety parts require magnetic particle inspection. [0003] According to the di...

AI Technical Summary

Problems solved by technology

Some human-assisted operations in traditional magnetic particle testing are difficult to carry out. How to ensure the accuracy of magnetic particle testing and replace cumbersome manual operations is a difficult problem that needs to be solved in the development of magnetic particle testing automation.

Images