空蚀坑周围彩虹区的形成机理

Investigation on the Formation of Iridescent Rings around Cavitation Erosion Pit

经过1 min的超声振动空蚀试验后,在不锈钢试样表面形成的空蚀坑周围出现环形彩虹区.表面检测结果表明,该区域经历了高于300℃的高温加热过程.数值计算结果表明在空泡溃灭形成的微射流的高速冲击下,试样表面材料在短时间内发生的塑性变形所释放出的能量是造成材料局部升温的主要原因.在塑性变形相同的情况下,材料的导热系数是影响彩虹环区域大小的关键因素.

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 300 ℃ 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.