Heat Dissipation Behavior of a Low-Strength-Steel Welded Joint in Ultrasonic Fatigue
Jiang-Tao Hu,
Rong Chen,
Gang Zhu,
Chong Wang,
Ming-Liang Zhu,
Fu-Zhen Xuan
Affiliations
Jiang-Tao Hu
Key Laboratory of Pressure Systems and Safety, Ministry of Education, School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237, China
Rong Chen
Key Laboratory of Pressure Systems and Safety, Ministry of Education, School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237, China
Gang Zhu
Key Laboratory of Pressure Systems and Safety, Ministry of Education, School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237, China
Chong Wang
Failure Mechanics and Engineering Disaster Prevention, Key Laboratory of Sichuan Province, Sichuan University, Chengdu 610207, China
Ming-Liang Zhu
Key Laboratory of Pressure Systems and Safety, Ministry of Education, School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237, China
Fu-Zhen Xuan
Key Laboratory of Pressure Systems and Safety, Ministry of Education, School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237, China
The coupled effects of heat and frequency in very-high-cycle fatigue are known under ultrasonic testing, while the heat dissipation behavior of welded joints is less investigated. In this work, the specimen surface temperature of a low-strength-steel welded joint and its base metal were monitored by infrared thermal imaging technique under ultrasonic fatigue loading. Results showed that the surface temperature distribution of both welded and base metal exhibited a parabola shape, and the temperature evolved with three stages. The location of the highest temperature within the weld metal correlated well with fatigue failure location. The inhomogeneity and asymmetry of temperature distribution implied a dominant role for heat transfer mode and insignificant influence of microstructure heterogeneity or specimen type. The nature of heat dissipation in low-strength steel in ultrasonic fatigue was thermal–mechanical coupling effect, which should be paid close attention in the standardization of ultrasonic fatigue testing.
