Abstract: The thick cylinder with half-embedded circular crack is selected as the research object. The crack arrest is accomplished by using electromagnetic heating due to pulse current discharge through the inside and outside circular surfaces. The complex function method is used to solve the temperature field and thermal stress field around the crack tip at the moment when the pulse current is switched on. The small welded joints can be formed at a small sphere near the crack tip inside the thick cylinder by metal melting as a result of heat concentration effect due to the pulse current discharge. The temperature around crack tip raises up instantly and over the melting point of metal .The curvature of the crack end will increase instantly. The thermal compressive stress is around the crack tip. So the formation of the main crack will be prevented. At the same time, the stress field around the crack tip under the action of mechanical load and electrical load is discussed.

Key words: half-embedded circular crack, crack arrest, pulse current, temperature field, thermal stress field