Develop new carbides for high-performance high-Cr cast irons (HCCIs) with optimized combination of fracture toughness and hardness

开发用于高性能高铬铸铁 (HCCI) 的新型碳化物，具有断裂韧性和硬度的优化组合

• 批准号: 522842-2017
• 负责人: Li, Dongyang
• 金额: $ 11.75万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Collaborative Research and Development Grants
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=657434
• 关键词: Develop; new; carbides; performance; Cr

High Chromium Cast Irons (HCCIs) are widely used in oil sands, mining, and manufacturing industries to resist wear and corrosive wear. The excellent performance of HCCIs results from the combination of hard carbides, e.g., M7C3, and a ferrous matrix. Commercially used HCCIs have their Cr and C contents in the range of 23-30 wt%Cr and 2-3wt%C, respectively. In recent years, the oil sands industry has made great efforts to push Cr and C contents to higher levels with more options for applications under aggressive and harsh conditions. However, raising %C and %Cr increases the material strength but lowers the fracture toughness due to promoted formation of coarse primary carbides, resulting in less impressive performance when encounter wear involving impact force and largely fluctuated wearing forces. Although the performance of HCCIs can be optimized through microstructure engineering, the improvement is limited due to the microstructure inhomogeneity in industrial-scale casting, vague design guidelines, and high costs in manufacturing. ** **Direct modification of carbides in HCCIs is an alternative approach for improved performance and simplified microstructure control. However, relevant research is rather limited due to the limitation of experimental and theoretical tools. The development of multimode atomic force microscope and computational materials science has made the research possible. This project is proposed to tailor carbides in HCCIs with a few promising approaches, including adding 3rd element to carbides, developing complex MC carbides, promoting core-shell structured carbides, and tailoring interfacial bonding between carbides and matrix. The proposed research is based on our successful preliminary studies, and will be conducted in collaboration with our industrial partners in Weir Minerals Canada. Developed knowledge and database will not only benefit the Canadian oil sands industry but also other technical sectors such as mining and manufacturing. Furthermore, the HQPs trained in this project will bring long-term benefits to Canada.

高铬铸铁(HCCI)广泛应用于油砂、采矿和制造业，以抵抗磨损和腐蚀磨损。HCCI的优异性能源于硬质碳化物(如M7C3)和铁基的结合。商业上使用的HCCI的铬和碳含量分别在23-30wt%铬和2-3wt%C的范围内。近年来，油砂行业努力将铬和碳的含量提高到更高的水平，在苛刻的条件下有更多的应用选择。然而，%C和%Cr的增加提高了材料的强度，但由于促进了粗大初生碳化物的形成，从而降低了断裂韧性，导致在涉及冲击力和磨损力波动较大的磨损时，性能较差。虽然可以通过显微组织工程来优化HCCI的性能，但由于工业规模铸造的组织不均匀、设计指南不明确以及制造成本较高，这一改进受到了限制。*碳化物的直接改性是改善性能和简化显微组织控制的替代方法。然而，由于实验和理论工具的限制，相关研究相当有限。多模原子力显微镜和计算材料科学的发展使这一研究成为可能。该项目旨在通过在碳化物中添加第三元素、开发复杂的MC碳化物、促进核壳结构碳化物以及剪裁碳化物与基体之间的界面结合等几种有前途的方法来定制HCCI中的碳化物。拟议的研究是基于我们成功的初步研究，并将与我们在伟尔矿业加拿大的工业合作伙伴合作进行。发达的知识和数据库不仅将使加拿大油砂行业受益，还将使采矿和制造等其他技术部门受益。此外，在该项目中培训的HQP将为加拿大带来长期利益。