|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Advanced High-strength Steels
||Effects of Matrix Microstructure on the Nanoscale Precipitation and Precipitation Strengthening in an Ultra-high Strength Steel
||Songsong Xu, Hao Guo, Yu Zhao, Naimeng Liu, Dan Chen, Ye Cui, Yang Zhang, Zhongwu Zhang
|On-Site Speaker (Planned)
The evolution of precipitation strengthening and its influence on the mechanical properties in the ultra-high strength steel have been studied through a combination of three dimensional atom probe tomography(APT), small-angle neutron scattering(SANS) and mechanical tests. The results indicated that these nanoclusters consisted of a Cu-enriched bcc core partially encased by a B2-order Ni(Mn,Al) phase, gradually grew with aging, leading to different mechanical properties. Yield strength of the steel increased slightly at under-aged condition and reached peak values of ~1768MPa at the aging peak, and then prolonged aging led to the decrease of yield strength due to an over-aging effect. Strengthening mechanism by quantitative calculation showed that small clusters at under-aged and peak aging would be all shearing. In this case, order strengthening and modulus strengthening provided synergistic effects on the mechanical properties of the steel. Beyond peak aging, the shear strengthening was suppressed and replaced by Orowan strengthening.
||Planned: Supplemental Proceedings volume