腐蚀疲劳交替环境下0Cr16Ni5Mo1不锈钢的损伤行为研究

目的 研究腐蚀疲劳交替环境下0Cr16Ni5Mo1不锈钢的损伤行为。方法 通过开展0Cr16Ni5Mo1不锈钢在不同腐蚀疲劳交替次数下的试验，分析腐蚀疲劳交替频率对疲劳寿命、表面形貌等的影响规律，明确其腐蚀疲劳交替损伤机理。结果 腐蚀时间一定时，0Cr16Ni5Mo1不锈钢试验件的疲劳寿命随着腐蚀疲劳交替频率的增加而增加。交替频次较低时，疲劳断裂部位主要发生在试验件表面或侧面的腐蚀损伤处；交替频次较高时，疲劳断裂部位开始内部缺陷处出现。试验件表面附着的腐蚀产物随着交替周期的进行而减少，但随着交替次数的增加，基体截面深处出现腐蚀产物。结论 0Cr16Ni5Mo1不锈钢试验件的疲劳寿命随交替次数的增加呈现指数函数规律的增长趋势。腐蚀-疲劳交替作用下，0Cr16Ni5Mo1不锈钢的表面腐蚀损伤形式主要为点蚀，裂纹主要萌生于试件表面的缺陷处，腐蚀加速了裂纹萌生的进程。交替次数的增加促进了表面和缺陷处钝化膜的生成，以及腐蚀产物在缺陷内部的堆积，从而使试验件寿命增大。

Damage Behaviour of 0Cr16Ni5Mo1 Stainless Steel under Alternating Corrosion and Fatigue Environment

The work aims to study the damage behavior of 0Cr16Ni5Mo1 stainless steel under alternating corrosion and fatigue environment. By carrying out the tests of 0Cr16Ni5Mo1 stainless steel for different times of alternating corrosion and fatigue, the effect the corrosion and fatigue alternation frequency on the fatigue life, surface morphology, etc. was analyzed and the damage mechanism of alternating corrosion and fatigue was clarified. When the corrosion time was constant, the fatigue life of 0Cr16Ni5Mo1 stainless steel specimen increased with the increase of corrosion and fatigue alternation frequency. When the alternation frequency was low, the fatigue fracture site mainly occurred at the corrosion damage on the surface or side of the specimen, and when the alternation frequency was high, the fatigue fracture site also began to appear at the internal defects. The corrosion products attached to the surface of the specimen decreased with the alternation cycle, but with the increase of the alternation frequency, the corrosion products appeared deep in the matrix section. The fatigue life of 0Cr16Ni5Mo1 stainless steel specimen shows an exponential function law growth trend with the increase in the alternation frequency. Under the action of corrosion-fatigue alternation, the surface corrosion damage of 0Cr16Ni5Mo1 stainless steel is mainly in the form of pitting corrosion, cracks mainly occur in the specimen surface defects and corrosion accelerates the process of crack initiation. The increase in the alternation frequency promotes the generation of surface and defects in the passivation film, and corrosion products in the defects of the internal accumulation, so that the specimen life increases.