Re-Nb微合金化C-Mn-Al-P系TRIP钢热加工过程中微观组织控制研究

TRIP钢的无Si化能显著改善其表面质量，从而拓展其应用范围，是TRIP钢开发的难点，申请人设计的C-Mn-Al-P成分基本实现了TRIP钢无Si化，但是抗拉强度略有不足。鉴于此，申请人拟依托地区特色资源-白云鄂博矿-采用Re-Nb复合微合金化思路对C-Mn-Al-P系TRIP钢进行强化，重点研究热加工过程中的组织控制机理，希望通过本项目研究对我国白云鄂博矿的综合利用提供新的途径。项目在分析Re、Nb含量对相变和微观组织的影响基础上，通过研究热加工过程中工艺对组织性能的影响，以获得最优的Re、Nb含量，并探索Re-Nb微合金化后TRIP钢的组织控制工艺。在此基础上，利用多尺度微观组织观察手段对热加工过程中各阶段各组织中C的分布和存在形式进行精确测量，结合分子动力学计算，对Re-Nb微合金化TRIP钢在热加工过程中C扩散行为进行研究，探讨Re-Nb微合金化后TRIP钢微观组织控制机理。

Removing Si from TRIP steel can significantly improve the surface quality and expand its application, which is also a difficult point for development. The applicant developed the TRIP steel without Si based on the C-Mn-Al-P composition. However, the tensile strength is slightly sufficient. In view of this, the applicant intends to strengthen the C-Mn-Al-P TRIP steel relying on the regional resources -baiyuneboite and applying Re-Nb microalloying. The research would focus on the microstructure controlling mechanism during hot working process in hope of providing new way for the comprehensive utilization of baiyuneboite. Based on the analysis of the influence of the Re, Nb content on the microstructure and phase transformation, the project would study the impact of process on microstructure and performance in the hot working process, in order to obtain the optimal Re, Nb content, and explore the microstructure controlling technology of TRIP after Re-Nb microalloying. Based on this, the distribution and existence form of C in different stages of the hot working process are precisely measured by the use of multi-scale microstructure observation methods. Combining with molecular dynamics calculation, the diffusion behavior of C during hot working is researched and the microstructure controlling technology of TRIP after Re-Nb microalloying is discussed.