321不锈钢表面空蚀行为研究

Cavitation Erosion Behavior of 321 Stainless Steel

目的:为了研究321不锈钢的抗空蚀性,在超声波金属材料空蚀试验机上对该材料试样进行了空蚀试验。方法:采用金相显微镜观察、维氏硬度测定、扫描电镜微观形貌分析和失重测量等多种表征方法研究了该材料的空蚀行为和特征。结果:试验表明,321不锈钢的空蚀经历了孕育期、上升期、衰减期和稳定期四个典型的空蚀阶段,该材料的空蚀坑具有明显的"彩虹环"特征。结论:由塑性变形和疲劳断裂引发的力学作用是321不锈钢表面空蚀损伤的主要机理,空泡溃灭引发的局部高温氧化是空蚀坑"彩虹环"的主要成因。

Objective： In order to study the corrosion resistance of 321 stainless steel,a cavitation erosion experiment of the material sample was performed in an ultrasonic vibration apparatus. Methods： The cavitation behavior and characteristics of 321 stainless steel were studied by means of metallographic microscope,vivtorinox hardness measurement,scanning electron microscopy（ SEM） and weight loss analysis. Results： The results showed that the cavitation of 321 stainless steel experienced four typical stages of cavitation erosion,which are incubation,rising,decline and stable period. The cavitation pits of the material exhibit obvious characteristics of ‘iridescent color ring＇. Conclusion： Mechanical effect of plastic deformation and fatigue fracture is the main mechanism of surface cavitation erosion,and the local high temperature oxidation caused by bubble collapse is the main reason of ‘iridescent color ring＇.