GOALI: The Origin of Slag-Metal Interface Defects in Electroslag Remelting

这项由普渡大学、海恩斯国际公司和特殊金属公司联合颁发的授予工业学术联系机会(GOALI)奖的研究目的是调查镍高温合金电渣重熔(ESR)中表面缺陷的原因。在电渣重熔过程中，液态渣帽位于液态金属池的顶部，液态金属池由从渣中掉落的熔融金属滴提供。随着工艺的进行，渣与金属的相互作用可能会在金属中嵌入渣块，并可能形成金属与模具接触的区域；这两种缺陷都需要时间、材料和能量。我们将开发一个数值过程模型来预测整个过程中炉渣-金属界面的行为、最终的表面粗糙度和块体钢锭的特性。此外，普渡大学的学生实习生将从工业过程中收集数据，以确定炉渣和周围金属中的缺陷结构。这项研究将揭示这类昂贵缺陷的可能形成机制，这些理解将被行业用来设计控制策略，提高产量，降低成本和能源使用。这个目标项目将通过合作研究和在行业实习中安置学生和教师来加强组织之间的联系。这些公司预计，他们的大部分新开发工作将是对能源行业的回应，该行业对更高的温度和压力以及更具腐蚀性的环境有更高的要求。只有适当的合金和工艺设计才能促进这些计划的实现，而本提案将对此有所帮助。合作伙伴关系密切，合作旨在让学生接触到对国家经济和安全至关重要的尖端工艺技术。PI将在海恩斯研究实验室度过一段时间的暑假，每家公司每年都会从普渡聘请一名暑期实习生，PI将包括本科生研究人员参与该项目。

The research objective of this Grant Opportunity for Academic Liaison with Industry (GOALI) award, executed jointly by Purdue University, Haynes International, and Special Metals Corporation, is to investigate the causes of surface defects in electroslag remelting (ESR) of nickel superalloys. During ESR, a liquid slag cap sits on top of a liquid metal pool which is fed by molten metal drops falling through the slag. As the process proceeds, slag-metal interactions can embed slag patches in the metal and can form regions in which the metal is in contact with the mold; both defects cost time, materials, and energy. We will develop a numerical process model to predict the behavior of the slag-metal interface throughout the process, the final surface roughness, and the bulk ingot characteristics. Also, Purdue student interns will collect data from industrial processes to determine the defect structure in the slag and the surrounding metal. This study will bring to light the possible formation mechanisms of this expensive class of defects, which understanding will be used by industry to design control strategies and to improve yield and lower costs and energy usage.This GOALI project will strengthen ties among the organizations through collaborative research and placement of students and faculty in industrial internships. These companies expect that most of their new development work will be in response to the energy sector, which has requirements for higher temperatures and pressures and more corrosive environments. Realization of these plans will only be facilitated by proper alloy and process design, which this proposal will aid. The partners are tightly connected and the collaborations are designed to expose students to cutting-edge process technology vital to the nation's economy and security. The PI will spend part of a summer at the Haynes research lab, each company will hire a summer intern from Purdue each year, and the PI will include undergraduates researchers in the project.