Effects of cooling process on the microstructure and mechanical properties of a novel high-V high-Mn TWIP steel for cryogenic storage tank applications

作者：Yong Chen, Xiao-Ming Zhang, Huan-huan Wang, Zhihui Cai, Huaying Li, Hua Ding, Guangming Liu · 发表于：Journal of Materials Research and Technology · 年份：2024 · DOI：10.1016/j.jmrt.2024.05.003 · 被引用次数：8 · 研究领域：Microstructure and Mechanical Properties of Steels、Metal Alloys Wear and Properties、Metallurgy and Material Forming

In the present work, a novel high-V high-Mn twinning induced plasticity (TWIP) steel for cryogenic storage tank applications was developed. Furthermore, innovative two-stage cooling processes encompassing ultra-fast cooling and the subsequent furnace cooling were proposed. Effects of cooling process on the microstructure and mechanical properties of the experimental steel were investigated. It was observed that with the change in cooling process (the initial temperature of furnace cooling rised gradually), the dwell time of hot-rolled plates above 600 °C was extended. The extension in dwell time facilitated the precipitation of secondary phase particles, leading to the change in average diameter and volume fraction of secondary phase particles. The yield strength increased with the increasing initial temperature of furnace cooling due to the combined effect of small-sized secondary phase particles inside the grains and large-sized ones located at the grain boundaries. The occurrence of intergranular cracking, primarily caused by the presence of large-sized secondary phase particles at the grain boundaries, was the main factor responsible for the significant reduction in total elongation. The small-sized secondary phase particles inside the grains inhibited deformation twinning, while the large-sized ones at the grain boundaries weaken the binding force between grain boundaries, which ultimately resulted in a decrease in cryogenic impact toughness. The implementation of two-st...