【作者】 刘琦；

【导师】 吴勇；

【作者基本信息】 机械科学研究总院 ， 材料学， 2011， 硕士

【摘要】 本文研究了渗氮渗锌复合处理新工艺,分析了复合渗层的组织和主要成分；研究了渗锌、渗氮和渗氮渗锌复合渗层在油井产出液环境下的的腐蚀学与摩擦学性能及其机理。本论文研究的主要内容和取得的主要成果有：1.研究了渗氮渗锌复合处理工艺,通过对试样先作离子渗氮处理,再渗锌,在45钢上制备出渗氮渗锌复合处理层。2.研究了复合渗层的成分和组织,发现渗层主要成分由Fe4Zn9、FeZn6.67和Fe8N组成,组织从表至里分别为61相、r相锌铁合金化合物层和渗氮扩散层。渗锌层的次表层(即渗氮扩散层)硬度明显高于单纯渗锌的基体硬度,形成良好的硬度梯度,有利于提高耐磨性能。对复合渗层的形成机理进行了探讨。3.对渗层腐蚀学特性进行了研究,分别测试了45钢、45钢渗锌层、45渗氮层和45渗氮渗锌复合渗层在油井产出液中的Tafel曲线,测得各种渗层在油井产出液废水中的自腐蚀电位和自腐蚀电流密度。发现渗锌层和复合渗层可以作为牺牲阳极对45基体提供阴极保护。渗氮层对基体不具有阴极保护功能。复合渗层具有比渗氮层更优秀的耐腐蚀性能。4.模拟油井产出液环境,研究温度和pH值对渗层在二氧化碳及溶解氧条件下耐腐蚀性能的影响。复合渗层、渗锌层、渗氮层在溶解氧、二氧化碳溶液中,自腐蚀电流以及腐蚀速率均随pH值减小而增大。在二氧化碳溶液中,复合渗层的腐蚀电流和腐蚀速率开始随温度的升高而增大,但到70℃时出现极大值,温度再升高,腐蚀电流和腐蚀速率反而下降；渗氮层的腐蚀电流和腐蚀速率则随温度的升高一直增大。这个结果表明复合渗层特别适用于油井产出液环境(一般工况温度为80℃)。5.研究了渗锌、渗氮和复合处理渗层在含砂的油井产出液中的摩擦磨损性能。研究结果表明：渗层的磨损量随油井产出液含砂量的增加而增加,其磨损机理为三体磨粒磨损。渗氮渗锌复合渗层的磨损率虽然高于渗氮层,但是低于渗锌层。6.渗氮渗锌复合处理具有优秀的综合耐腐蚀抗磨损性能。更多还原

【Abstract】 This paper, studied the new technology of the nitriding and sherardizing complex treatment; analyzed the main component and organization of the composite layer; investigated the behavior and mechanism of corrosion and friction of nitriding、sherardizing and complex treatment in oil output.The main content and achievements of this paper are as follows:1. The nitriding and sherardizing complex treatment technology had been studied. After nitriding and then sherardizing, the complex treatment layer was prepared on 45 steel.2. By Studying the composition and organization of the complex treatment layer, we found the main components is Fe4Zn9、FeZn6.67 and Fe8N, from the surface to the bottom of layer wereδ1 phase,Γphase of Zn-Fe alloy layer and nitriding diffusion layer. The hardness in nitriding diffusion layer in remarkably higher than that in the pure sherardizing matrix which forms a good hardness gradient to improve the behavior of wear resistance. Meanwhile, we discussed formation mechanism of complex penetration layer.3. The corrosion behavior of several penetration layers had been studied. The Tafel curve for 45 Steel, sherardizing layer of 45 Steel, nitriding layer of 45 Steel layer and nitriding and sherardizing complex layer of 45 Steel had been measured and the corrosion potential and corrosion current density had been obtained in oil output. The sherardizing treatment and the complex treatment can be used as sacrificial anode substrate on the 45 steel to provide protection, the nitriding cann’t provide this protection. Complex layer has better performance of corrosion resistance than that of the nitriding layer.4. Simulate the effect of the environment in oil output, research temperature and pH value to corrosion resistance behavior in the penetration layer in CO2 and O2 corrosion solution system. The corrosion current and corrosion rate increase with the diminution of pH value for the complex layer, sherardizing layer and nitriding layer. In CO2 corrosion solution system, the corrosion current and corrosion rate were increased with temperature increasing for the complex layer, and had those maximum at 70℃, then they would decrease with temperature increasing. However, in nitriding layer, they will always increase with the temperature increasing. The result shows that complex penetration layer is very suitable in oil output liquid, (mostly T=80℃).5. The efforts of sherardizing, nitriding and complex treatment on the friction and wear behavior had been studied. The results showed that:the loss wear of the penetration layer increase with the sand content of oil output liquid, the wear mechanism of is three-body abrasive wear. The wear rate of the complex treatment samples was larger than nitriding samples, but the wear rate of complex treatment samples was lower than sherardizing samples.6. The complex treatment has excellent antiwear and corrosion resistance properties.更多还原