Abstract: In the ultrasonic vibration cavitation erosion experiment, iridescent rings were observed around erosion pits on the stainless steel surface after one-minute test. Surface observations indicated that the zones within the iridescent rings experienced a tempering process at 300oC or even higher. Here, the deformation process of the damaged surface was numerically simulated, and the heat released during this process was a possible way to form the iridescent rings. Also, the thermal conduction coefficient greatly affected the ring size.