%A Xi‑kou He, Zhi‑qiang Yang, Zhen Wang, Shi‑bin Qiao, Zheng‑dong Liu %T Effect of Mn content on microstructure, tensile and impact properties of SA508Gr.4N steel for reactor pressure vessel %0 Journal Article %D 2020 %J 钢铁研究学报(英文版) %R 10.1007/s42243-020-00393-1 %P 461-470 %V 27 %N 4 %U {http://www.chinamet.cn/Jweb_gtyjxb_en/CN/abstract/article_151914.shtml} %8 2020-04-25 %X The effect of manganese (Mn) on the microstructure, tensile and impact properties of SA508Gr.4N steel has been experimentally investigated. The influence of Mn content on the substructure of SA508Gr.4N steel was investigated using the scanning electron microscope, electron back-scattered diffractometer and transmission electron microscope. It was found that the increased Mn content had a beneficial effect on both strength and toughness. Examination of microstructure revealed smaller size of block and larger number of high-angle grain boundaries with higher Mn content. The change of the ultimate tensile strength and toughness with increasing Mn content was attributed to the increased hardenability, the number of high-angle grain boundaries and the crack propagation path by the block refining.