A Review on Nano-Scale Precipitation in Steels

Abstract

Nano-scale precipitation strengthened steels have drawn increasing attention from the materials community recently due to their excellent mechanical behaviors at room temperature, high specific strength to weight ratio, superior radiation resistivity, good weldability, and many more to mention. With the advent of technology, such as synchrotron X-ray, atom probe tomography (APT), and high resolution transmission electron microscopy (HR-TEM), probing precipitates down to the atomic level has been made possible. In this paper, various nano-scale precipitate strengthened steels are compiled with the aim to identify the effects of size and number density of precipitates on the mechanical properties. Besides, the strengthening mechanisms, slip systems, and dislocation-precipitate interactions are reviewed. Moreover, the nucleation and stability of precipitates are also discussed. Finally, the challenges and future directions of the nano-scale precipitate strengthened steels are explored.

Keywords

• nano-scale precipitation strengthened steel
• size and number density of precipitates
• precipitate-interface segregation
• coherency
• strengthening mechanism
• slip system
• dislocation
• stability