Technique for producing crack arrest by electromagnetic heating

Abstract

Crack arrest in current conducting materials by electromagnetic heating can be used effectively to extend the service life and improve the safety and reliability of structures and components. Theoretical analysis and experimental investigations have shown that due to heat concentration around the crack tip, small welded joints are formed by metal melting. Thus, the formation of the main crack source is prevented. From metallography, it has been found that a typical fine phase transformation microstructure can be obtained in the crack tip region as a result of rapid heating and cooling. The intensity, ductility, and wear capacity are promoted under the combined influence of superfine structure, thermal compressive stresses, and phase transformation compressive stresses. Microcracking and subsequent main crack propagation can both be prevented. The basic principles of the electromagnetic heating effect and the results of experimental work based on the theory are presented.