Stress and Creep Damage Evolution in Materials for Ultra-Supercritical Power Plant

未来的化石发电厂将不得不在更高的温度下运行，以提高其热效率并减少其碳足迹。高铬马氏体钢（如P91、P92）已被开发用于高温应用，并越来越多地用于超临界电站，但在使用中焊接件周围存在早期开裂迹象。需要了解和量化导致这些故障的基本物理和微观机制，以便开发新的设计和寿命评估方法。这项培训研究提案的目的是在中央设施开发中子和同步辐射测量技术的潜力。该技术将被应用于测量制造残余应力在多个长度尺度的高铬焊件和量化他们如何放松在服务高温暴露，测量和空间解决跨焊件的塑性和蠕变变形，并量化体积蠕变空穴导致开裂的演变。该项目将使用ENGIN-X，LOQ和SANS_2D仪器在ISIS和JEEP在钻石，并涉及学生花费四个培训实习这些仪器。该项目与开放大学的高温材料能源研究计划密切相关，学生将有机会获得补充测试设施。焊接试样将由欧洲技术开发有限公司提供，该公司的参与将促进先进测量技术的结果和能力向全球发电行业的传播。

Future fossil power generation plant will have to operate at higher temperatures to increase its thermal efficiency and reduce its carbon footprint. High-chromium martensitic steels (such as P91, P92) have been developed for elevated temperature applications and are being used increasingly in supercritical power stations, but there are early signs of cracking around weldments in service. The underlying physics and micro-mechanisms contributing these failures needs to be understood and quantified so that new design and life assessment methods can be developed. The aim of this training research proposal is to exploit the potential of neutron and synchrotron radiation measurement techniques at Central Facilities. The techniques will be applied to measure fabrication residual stresses at multiple length-scales in high Cr weldments and quantify how they relax during service high temperature exposure, to measure and spatially resolve plastic and creep deformation across weldments, and to quantify volumetrically the evolution of creep cavitation leading to cracking. The project will use ENGIN-X, LOQ and SANS_2D instruments at ISIS and JEEP at Diamond and involve the student spending four training placements these instruments. The project fits closely with a programme of high temperature materials for energy research at the Open University where the student will have access to complementary test facilities. Welded test specimens will provided by European Technology Development Ltd whose involvement will facilitate dissemination of the results and capabilities of advanced measurement techniques to the power generation industry worldwide.