Development of Commercializable High-Performance High-Cr Cast Irons through Multi-Level Control

阿尔伯塔省/加拿大的油砂工业是世界上探明原油储量第三大的国家，在保证国家燃料自给自足方面发挥着重要作用。然而，油砂开采的高成本使得该行业容易受到油价波动的影响，从而动摇国民经济，目前油价下跌对加拿大经济的影响就是证明。必须通过降低油砂生产的高成本来改变这种状况，以增加加拿大经济对石油冲击的抵抗力。油砂作业的一大成本来自于油砂浆输送系统（如浆泵）磨损部件的维修和更换。虽然为开发坚固材料作出了重大努力，但由于缺乏有效制造的材料设计和控制的健全指导方针，成功是有限的。本研究旨在研究用于油砂浆输送的高性能高铬铸铁（HCCIs）。申请人的团队与Suncor合作，对新型hcci进行了广泛的研究，这些hcci表现出了卓越的性能。然而，当考虑到材料的实际应用时，存在两个主要问题：1)高成分敏感性，即成分的微小变化会导致材料性能的巨大变化；2)工业铸造条件下的成分不均匀性使得实验室形成的组织难以复制。因此，根据所需的性质扩大样本量是至关重要的。否则，已开发的hcci无法得到实际利用，行业和政府的投资也无法获得预期的回报。本项目拟进一步优化新型hcci，重点通过多级控制降低成分敏感性，研究铸锭尺寸对成分/显微组织均匀性的影响，使优化后的hcci可工业化生产，并具有良好的工艺控制指导和有效的应用。

With the third-largest proven crude oil reserve in the world, the Alberta/Canadian oil sand industry is playing an important role in guaranteeing the national fuel self-sufficiency. However, the high cost of extracting oil from oil sand makes this industry vulnerable to oil price fluctuations, which trembles the national economy, evidenced by the impact of current oil price drop on Canadian economy. Such a situation must be changed through reducing the high cost of oil sand production in order to increase resistance of Canadian economy to oil-shock. One of large costs in oil sand operation comes from repair and replacement of worn components in oil sand slurry transport system, e.g., slurry pumps. Although significant efforts have been made to develop strong materials, success is limited since there is lack of sound guidelines for material design and control towards effective manufacturing. This proposed work is aimed at high-performance high-Cr cast irons (HCCIs) for oil sand slurry transport. The applicant's group has carried out extensive research on new HCCIs in collaboration with Suncor, which have demonstrated exceptional performance. However, two main issues exist when the materials are considered for realistic applications, which are 1) high composition sensitivity i.e., minor changes in composition cause large variations in material performance; and 2) composition inhomogeneity under industrial casting condition makes it difficult to duplicate microstructures developed in laboratory. Thus, it is crucial to scale up the sample size with desired properties. Otherwise, the developed HCCIs cannot be realistically utilized and the investment from industry and government would not receive anticipated return. This project is proposed to further optimize the new HCCIs with focus on reducing the compositional sensitivity through multi-level control and investigating size effect of ingot on composition/microstructure homogeneity in order to have the optimized HCCIs producible on industrial scale with sound guidelines for process control and effective applications.