基本信息
项目批准号：51671190
申请代码：E0104
项目名称：先进超高强钢搅拌摩擦焊超细组织演化与力学行为研究
项目负责人：
薛鹏
依托单位：
中国科学院金属研究所
研究期限：2017-01-01 至 2020-12-31
资助经费：60.0（万元）
项目摘要
中文摘要：
在汽车工业需求的牵引下，先进超高强钢（AUHSS）受到了越来越广泛的关注。然而采用传统熔化焊工艺对AUHSS焊接时焊缝组织极易粗化、热影响区软化严重，限制了这种新型材料的广泛应用。搅拌摩擦焊(FSW)为固态连接技术，采用低热输入的FSW可大幅降低接头的软化，为AUHSS提供了一种理想的高质量焊接工艺。本项目以宝钢生产的两种典型AUHSS—双相钢DP1180和淬火配分钢Q&P1180为研究对象，在低热输入参数下进行FSW，通过对焊核区超细组织的演变及力学行为的深入研究，揭示在FSW大塑性变形和温度共同作用下钢的晶粒细化及相转变机制，加深对钢的典型超细晶组织静态及动态力学行为的理解，阐明不同特征的晶界及相界在变形过程中与位错的交互作用机制，探讨通过微观组织优化提高AUHSS力学性能的可能性，从而为AUHSS接头结构优化设计提供实验依据和理论指导。
英文摘要：
Advanced ultra-high strength steel (AUHSS) has received more and more attention due to the large demand in automotive industry. However, coarse structures easily formed in weld zone of traditional fusion welded AUHSS, and serious softening ocurred usually at heat affected zone, which severely restrict the wide application of AUHSS. Friction stir welding (FSW) is a solid state joining technology, and weld softening can be greatly reduced under low heat input, providing an ideal method in welding of AUHSS with sound properties. In this project, two typical AUHSS of dual phase steel (DP 1180) and quenching and partitioning steel (Q&P 1180) produced by Bao Steel Group will be FSWed with low heat input. Based on the investigation of microstructral evolution and mechanical behaviors of the ultra-fine strucutres in the weld zone of FSW AUHSS joints, the grain refining and phase transformation mechanisms under the combination of severe plastic deformation and high temperature are expected to be well explained, static and dynamic deformation behaviors of typical ultra-fine grained steels will be further understood, and the relationship between dislocations and different grain boundaries and phase boundaries during deformation will be clarified. Meanwhile, new methods of improving the mechaical properties of AUHSS via adjusting the microstructure will be discussed.The results of this project will provide essential experimental data and theory support for the optimized design on the microstructure of the AUHSS welds.
——来自https://kd.nsfc.gov.cn/
