本课题自2017年7月立项以来，基于“低温强韧化、超长疲劳寿命化”设计理念，完成了5 组中碳CrNiMoV 合金体系成分与组织设计，开展了冶金质量、微观组织对常低温韧性和疲劳性能的影响以及低温条件下车轴钢断裂力学行为及止裂机理研究，阐明了低温强韧化与长疲劳寿命化的精细组织与第二相调控机制，获得了优化的、可供工业试制的合金与组织设计方案及关键轧制工艺参数，形成了满足项目要求的原型钢，工业试制钢力学性能和超高周疲劳性能全部达到了任务书要求。形成科技报告7 份，申报专利7 项，获得授权专利6 项，发表文章10篇。

Since the establishment of this project in July 2017, based on the design concept of "low temperature strengthening and toughening, ultra- long fatigue life", the design of the composition and microstructure of 5 groups of medium carbon CrNiMoV alloy systems has been completed. Carried out the research on the influence of metallurgical quality and microstructure on normal/low temperature toughness and fatigue performance, as well as the fracture mechanics behavior and crack arrest mechanism of axle steel under low temperature conditions. Clarified the control mechanism of the fine structure and the second phase for low temperature strengthening and toughening and long fatigue life, and obtained optimized alloys for industrial trial production, microstructure design schemes and key rolling process parameters. A prototype steel meeting the requirements of the project was formed, and the mechanical properties and ultra-high cycle fatigue properties of the industrial trial-produced steel all met the requirements of the task book. Formed 7 scientific and technological reports, declared 7 patents, obtained 6 authorized patents, and published 10 article.