新型Cu-Ni-Al合金在人工海水中耐蚀性能研究

发布时间：2018-03-23 19:54

本文选题：Cu-Ni-Al合金　切入点：人工海水　出处：《河南科技大学》2017年硕士论文

【摘要】：随着我国“一带一路”、“科技兴海”等重大战略工程的实施,对耐蚀铜合金的需求日益迫切。以海洋工程用耐蚀铜合金为例,年需求量约40万吨,年产值约350亿元。同时,复杂多变的海洋条件使得耐蚀铜合金的服役条件日益苛刻,关键部件的安全可靠性越来越高,对合金的耐蚀性能提出了更高要求。然而,目前研究和应用较多的传统黄铜、B10、B30等耐蚀铜合金无法满足高端领域使用要求。因此,在传统Cu-Ni系耐蚀铜合金的基础上,开展苛刻服役条件下新型高耐蚀铜合金的设计开发以及耐蚀机理研究,对于我国海洋工程用耐蚀铜合金的基础理论研究和工程化应用具有重要意义。本文针对上述问题,在传统Cu-Ni系耐蚀铜合金的基础上,通过添加Al、Fe、Mn、RE等微合金化元素,制备了新型Cu-Ni-Al耐蚀铜合金;通过静态人工海水全浸试验,研究了海水浸泡时间对合金腐蚀速率和腐蚀形貌的影响规律,揭示了稀土添加量与耐蚀性能的内在关联;通过电化学测试手段,研究了海水浸泡时间与合金电化学阻抗谱等电化学性能的内在联系,探索了稀土添加量对合金电化学行为的影响规律;通过海水冲刷试验,研究了冲刷速度和时间对合金腐蚀速率和腐蚀形貌的影响规律,揭示了稀土对合金冲刷腐蚀行为的作用机制。研究结论如下:1.浸泡条件下,Cu-Ni-Al合金和添加0.014%RE、0.035%RE的Cu-Ni-Al合金的腐蚀速率变化规律均为:初期腐蚀速率较大,随浸泡时间延长,合金表面钝化膜开始形成并逐渐完善,合金腐蚀速率降低并趋于平稳;在浸泡条件下,随着稀土的添加,合金耐腐蚀性能提高,腐蚀速率降低,168 h时添加0.014%RE、0.035%RE的Cu-Ni-Al合金腐蚀速率分别比Cu-Ni-Al合金降低26%和29%,添加0.035%RE的Cu-Ni-Al合金耐腐蚀性最好。2.浸泡条件下,Cu-Ni-Al合金和添加0.014%RE、0.035%RE的Cu-Ni-Al合金的电化学行为变化规律相同,在浸泡初期,12 h时电化学阻抗谱中开始出现容抗弧,此时合金表面已经开始形成钝化膜,随浸泡时间延长,容抗弧半径增大,三种合金均在168 h时达到稳定,合金表面钝化膜处于溶解与生成的动态平衡之中;在浸泡条件下,随着稀土的添加,合金自腐蚀电位提高,腐蚀电流密度降低,添加0.035%RE的Cu-Ni-Al合金自腐蚀电流密度最低为2.179×10-6 A·cm-2,比Cu-Ni-Al合金和添加0.014%RE的Cu-Ni-Al合金分别降低24.2%和24.1%。3.在流动海水中,相同流速下Cu-Ni-Al合金和添加0.014%RE、0.035%RE的Cu-Ni-Al合金的腐蚀速率变化规律均为:初期腐蚀速率较高,随冲刷时间延长,合金腐蚀速率降低并趋于稳定,合金表面钝化膜随时间延长逐渐完善,性能提高;不同流速下Cu-Ni-Al合金和添加0.014%RE、0.035%RE的Cu-Ni-Al合金的腐蚀速率变化规律有所差异,1.5 m/s条件下初期12 h到24 h时合金腐蚀速率降低较快,合金表面钝化膜形成后较为稳定不易受到破坏;24 h到96 h期间随着流速增大,合金腐蚀速率升高,合金表面钝化膜易受到海水冲击作用而破坏;96 h后合金腐蚀速率趋于稳定,合金表面钝化膜已经达到稳定状态。4.在流动海水中,随着稀土添加,合金耐腐蚀性能提高,在1.5 m/s和3.0m/s流速下,合金腐蚀速率相差不大,但添加稀土的合金钝化膜性能较好,合金腐蚀速率降低较快;在5.0 m/s流速下合金初期腐蚀速率差异较小,随时间延长,添加稀土的合金腐蚀速率较低,合金钝化膜性能更优,耐蚀性能提高,添加0.035%RE的Cu-Ni-Al合金腐蚀速率为0.1488 g·m-2·h-1,腐蚀速率比Cu-Ni-Al合金降低43%。
[Abstract]:Along with our country "The Belt and Road", "the implementation of major strategic project technology and the sea", on the corrosion resistance of copper alloy. With the increasingly urgent demand for marine engineering alloy as an example, the annual demand of about 400 thousand tons, the annual output value of about 35 billion yuan. At the same time, the complex sea conditions make the service condition to corrosion the copper alloy has been harsh, safety and reliability of key parts of more and more high, put forward higher requirements on the corrosion resistance of alloys. However, more research and application of traditional brass, B10, B30 alloy can not meet the high-end use requirements. Therefore, based on the traditional Cu-Ni system on corrosion resistance of copper alloy to carry out the design and development of new service demanding, high corrosion resistance and corrosion resistance of copper alloy under the condition of mechanism research for corrosion resistance of copper alloy based on theoretical research and engineering application significance of Ocean Engineering in China. In this paper. The problem, based on the traditional Cu-Ni system on corrosion resistance of copper alloy, with the addition of Al, Fe, Mn, RE and other micro alloying elements, the new Cu-Ni-Al alloy was prepared by static; artificial seawater immersion test, the influence law of the alloy corrosion rate and morphology of the seawater immersion time was studied, revealing internal connection and corrosion resistance of rare earth content; by means of electrochemical testing, analyzing the relation between seawater immersion time and alloy electrochemical impedance spectroscopy electrochemical performance, explores the influence of the addition of rare earth alloys on the electrochemical behavior of the law; through sea water scouring, influence on the alloy corrosion rate and corrosion morphology and scouring velocity time study, reveal the mechanism of rare earth on erosion corrosion behavior of the alloy. The research conclusions are as follows: 1. soaking condition, Cu-Ni-Al alloy and Cu-Ni-Al alloy added 0.014%RE, 0.035%RE The corrosion rate changes are: the initial corrosion rate is high, with the increase of immersion time, the alloy surface passivation film began to form and gradually improve, corrosion rate of the alloy decreases and tends to be stable; in immersion conditions, with the addition of rare earth alloy, and improve corrosion resistance, the corrosion rate decreased, adding 0.014%RE 168 h, Cu-Ni-Al alloy the corrosion rate of 0.035%RE were 29% and 26% lower than that of Cu-Ni-Al alloy, corrosion resistance of Cu-Ni-Al alloy.2. the best soaking conditions of adding 0.035%RE, Cu-Ni-Al and 0.014%RE alloy added, the electrochemical behavior changes of Cu-Ni-Al alloy 0.035%RE the same, at the initial stage of immersion, electrochemical impedance spectroscopy of 12 h began to appear in the capacitive arcs, this alloy surface has been to form a passive film, with the increase of immersion time, increasing the capacitance arc radius of three alloys, reached the stable at 168 h, the alloy surface passivation film in solution With the dynamic balance of generation; in immersion conditions, with the addition of rare earth alloy, corrosion potential, corrosion current density decreased, the addition of 0.035%RE Cu-Ni-Al alloy, the corrosion current density for a minimum of 2.179 * 10-6 A, cm-2, and 24.1%.3. decreased by 24.2% in flowing seawater respectively than that of Cu-Ni-Al alloy and Cu-Ni-Al alloy added 0.014%RE Cu-Ni-Al, the same flow rate and the addition of 0.014%RE alloy, the corrosion rate of change of Cu-Ni-Al alloy 0.035%RE are: the initial corrosion rate is high, with scouring time, corrosion rate of the alloy decreased and stabilized, the passivation film on the surface of alloy gradually perfect, improve the performance of Cu-Ni-Al alloy under different velocity; and adding 0.014%RE, corrosion the rate of change of Cu-Ni-Al alloy 0.035%RE the difference under the condition of 1.5 m/s at the beginning of 12 h to 24 h alloy corrosion rate decreased rapidly, alloy The surface passivation film after the formation of a more stable are not easy to be damaged; 24 h to 96 h during the period with increased velocity increases and the corrosion rate of the alloy, alloy surface passivation membrane is susceptible to water impact damage; after 96 h alloy corrosion rate tends to be stable, the alloy surface passivation film has reached a steady state in flowing seawater with.4.. Addition of rare earth alloy, the corrosion resistance is improved, at 1.5 m/s and the 3.0m/s flow rate, corrosion rate of the alloy are similar, but the addition of rare earth alloy passivation performance good, corrosion rate of the alloy decreases quickly; at a flow rate of 5 m/s alloy at the initial corrosion rate difference is small, with time prolonging, the corrosion rate of the alloy of rare earth is low. The performance of passive film alloy has better corrosion resistance, the corrosion rate of Cu-Ni-Al alloy increase, adding 0.035%RE 0.1488 G - m-2 - H-1, the corrosion rate of 43%. lower than that of Cu-Ni-Al alloy

【学位授予单位】：河南科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG172.5

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