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

阿尔伯塔省/加拿大油砂行业拥有世界第三大已探明原油储量，在保障国家燃料自给自足方面发挥着重要作用。然而，从油砂中开采石油的高昂成本使该行业容易受到油价波动的影响，当前油价下跌对加拿大经济的影响就是明证。为了提高加拿大经济对石油冲击的抵抗力，必须通过降低油砂生产的高成本来改变这种状况。油砂作业的一大成本来自修复和更换油砂泥浆输送系统中的磨损部件，如渣浆泵。虽然已经做出了重大努力来开发坚固材料，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。这项工作是针对油砂泥浆输送用高性能高铬铸铁进行的。申请人的小组与森科尔合作，对新的HCCI进行了广泛的研究，表现出了出色的表现。然而，在考虑材料的实际应用时，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使实验室开发的显微组织难以复制。因此，根据所需的特性放大样本大小是至关重要的。否则，已开发的HCCI无法得到实际利用，行业和政府的投资也得不到预期的回报。本项目的目的是进一步优化新的HCCI，重点是通过多级控制降低成分敏感性，并研究钢锭尺寸对成分/显微组织均匀性的影响，以便使优化的HCCI能够在工业规模上生产，并为工艺控制和有效应用提供合理的指导。

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.