Welding processes used with Nickel-Aluminium Bronze components for service in the marine environment

用于海洋环境中的镍铝青铜部件的焊接工艺

• 批准号: 2267399
• 金额: --
• 依托单位: University of Bristol
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2019
• 资助国家: 英国
• 起止时间: 2019 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2267399
• 关键词: Welding; processes; used; Nickel; Aluminium

Nickel-Aluminium Bronze (NAB) is widely used in seawater-contacting marine components such as external fixings, propellers and valves due to its good corrosion resistance and biofouling resistance. However, the development of welding processes that produce a favourable microstructure and mechanical properties in this alloy system is challenging, so welds in NAB are much more vulnerable to corrosion and Stress Corrosion Cracking (SCC) than the wrought material. This limits the maintainability of NAB parts and makes expensive replacement programmes necessary.In this project, the structural properties and corrosion resistance of NAB welds produced using different welding processes will be analysed, along with those of steel welds for comparison. NAB and steel welds will be exposed to marine environments while being simultaneously stressed and both the corrosion rate and community of biofouling organisms will be monitored. We will link this information to analysis of the material's final state via optical and electron microscopy and X-ray diffraction, and to results from mechanical tests which will be performed on welds post-exposure. This will enable us to identify welding processes which produce favourable weld microstructure and crystallographic in this material, to determine the dominant processes involved in NAB weld degradation, and to predict the effects of corrosion on the long-term structural integrity of NAB welds. During the environmental tests, we will also investigate the link between marine biofouling and corrosion damage. This will allow us to develop more practical, biologically-based corrosion inspection methods for marine welds.This work aligns with the Materials Engineering (Metals & Alloys) area of EPSRC's Manufacturing the Future theme. We will improve welding methods both for manufacturing NAB components and for NAB component repair by developing a greater understanding of how weld microstructures relate to corrosion-based degradation mechanisms. This will lead to economic benefits to operators of vessels and offshore structures, and to the UK marine maintenance industry. A direct practical outcome of this work will be to inform the welding processes used in Repair and Overhaul (R&O) by the industrial project partner Babcock International Group. It will also act as an enabling technology for the use of additive manufacturing (esp. Wire + Arc Additive Manufacturing) of NAB as an alternative to casting for creating complex-shaped components, which is currently under development by several major manufacturers. We also aim to link microstructure to biofouling for the first time, which will enable provide techniques for corrosion detection in NAB components, benefitting the safety and maintainability of offshore infrastructure

镍铝青铜（NAB）具有良好的耐腐蚀性和耐生物污性，广泛应用于外部固定件、螺旋桨、阀门等与海水接触的船用部件。然而，在这种合金体系中产生良好的微观结构和机械性能的焊接工艺的发展是具有挑战性的，因此NAB中的焊缝比锻造材料更容易受到腐蚀和应力腐蚀开裂（SCC）的影响。这限制了NAB部件的可维护性，并使昂贵的更换程序成为必要。在这个项目中，将分析采用不同焊接工艺生产的NAB焊缝的结构性能和耐腐蚀性，并与钢焊缝进行比较。NAB和钢焊缝将暴露在海洋环境中，同时受到应力，并监测腐蚀速率和生物污染生物群落。我们将把这些信息与通过光学和电子显微镜以及x射线衍射对材料最终状态的分析联系起来，并与焊接暴露后进行的力学测试结果联系起来。这将使我们能够确定在这种材料中产生有利的焊缝微观结构和结晶学的焊接工艺，确定NAB焊缝退化的主要工艺，并预测腐蚀对NAB焊缝长期结构完整性的影响。在环境试验期间，我们还将调查海洋生物污染与腐蚀损害之间的联系。这将使我们能够为海洋焊缝开发更实用的、基于生物的腐蚀检测方法。这项工作与EPSRC的“制造未来”主题的材料工程（金属和合金）领域相一致。我们将通过深入了解焊接微结构与基于腐蚀的降解机制的关系，改进NAB组件制造和NAB组件修复的焊接方法。这将为船舶和海上结构的运营商以及英国海洋维修行业带来经济效益。这项工作的直接实际成果将是为工业项目合作伙伴巴布科克国际集团在维修和大修（R&O）中使用的焊接工艺提供信息。它还将作为使用NAB的增材制造（特别是线+弧增材制造）的使能技术，作为铸造制造复杂形状部件的替代方案，目前正在由几家主要制造商开发。我们的目标是首次将微观结构与生物污垢联系起来，这将为NAB组件的腐蚀检测提供技术，有利于海上基础设施的安全性和可维护性