基本信息
项目批准号：U1660201
申请代码：E04
项目名称：高热强性低活化铁素体/马氏体钢组织设计及其搅拌摩擦焊接
项目负责人：
刘永长
依托单位：
天津大学
研究期限：2017-01-01 至 2020-12-31
资助经费：256.0（万元）
项目摘要
中文摘要：
核电建设正迎来战略发展机遇期，以核电为代表的高端科技出口已成为推动我国经济发展的重要力量，这其中迫切需要实现核电关键部件的国产化。低活化铁素体/马氏体钢广泛应用于先进快堆燃料组件包壳管和外套管，以及未来聚变堆包层结构，进一步提高其热强性和辐照稳定性对改善建设机组的热效率及安全可靠性具有重要意义。本项目拟在前期已完成的火电用高Cr铁素体耐热钢的研发基础上，依据低活化元素选取原则，在钢材合金成分设计中重点考虑W、Ta组元间的交互作用，以及痕量Zr组元的添加；在组织设计中突出亚晶强化和沉淀相复合强化机制，实现纳米级高热稳定性沉淀相对细化马氏体板条界的有效钉扎作用。由于已在核聚变包层模块应用的扩散连接技术受炉体尺寸限制，难以完成大工件连接，拟开展低活化铁素体/马氏体钢搅拌摩擦焊工艺探索及优化，阐明接头高温强度退化机制，提出相应强化方法，实现构件整体高温性能的一致性，从而为核电高端制造产业发展助力。
英文摘要：
With the promising development opportunity for nuclear power construction, the high-technology export with nuclear power as the representative has been turned into one key role to promote our country's economic development, which makes urgent requirements for the localization of key components for nuclear power equipment. Reduced activation ferritic/martensitic (RAFM) steels have been widely used as the candidate structural materials for cladding and outer tubes of fuel assemblies in advanced fast reactors, and the primary structural materials for cladding structure in future fusion reactors. To improve the thermal efficiency and safety of the nuclear power plants, it is essential to further improve the heat resistance and radiation stability of the RAFM steels. In this project, based on the previous completed studies on high Cr ferritic heat-resistant steel for power plants and the selection principle for reduced activation elements, regarding the composition design and optimization, attention would be focused on the combined effects of W and Ta on microstructure and mechanical performance of RAFM steels, as well as the trace addition of Zr, with respect to the microstructure modification, the strengthening mechanism combining sub-boundary hardening and precipitation hardening would be stressed, aimed at attaining the refined martensite laths that are pinned by the nano-scale precipitates with high thermal stability. Considering the limitations of diffusion bonding technology (adopted in the manufacture of cladding part of fusion plant) in joining large sized parts, the exploration and optimization of friction stir welding process for RAFM steels would be conducted, and the strength degradation mechanisms of the joints would be clarified. The strategies to improve the reliability of the friction stir welded joints would also be developed, to ensure the consistent high-temperature performance of the overall joined component and promote the development of nuclear advanced manufacturing industry.
——来自https://kd.nsfc.gov.cn/
