Fatigue Properties of ASTM A572 Gr65 Steel after Ultrasonic Surface Rolling Evaluated by Infrared Thermography

The surface of ASTM A572 Gr65 steel was treated with ultrasonic surface rolling technology, and combined with infrared thermal imaging method, the effects of ultrasonic surface rolling treatment on the fatigue properties of the material were explored. The results show that the samples have the same surface temperature change law as the untreated samples during the fatigue process, the surface properties of the samples improves, the near-surface grains are refined, and the fatigue property of the material is significantly improved. The fatigue limit of the rolled material obtained by the infrared thermal imaging method is 515 MPa, which is increased by 21.7% compared with the untreated 423 MPa. The fatigue limit obtained by the traditional S-N curve method increases from 458 MPa to 531 MPa, which is increased by 16%.