M23C6 chromium-rich carbides are common grain-boundary precipitation in Cr-containing steel. The presence of grain-boundary carbides often leads to intergranular brittleness and decreases the steel's mechanical properties. This study proposes a deformation and aging technique to obtain a high-volume-fraction dispersion distribution of the hard nano-M23C6 phase by changing the nucleation sites from grain boundaries to deformation coherent twin boundaries produced during cold deformation. The M23C6 precipitation-strengthened austenitic stainless steel has a strength of up to 1.4 GPa but maintains favorable plasticity (> 11%). This study provides a novel approach for the control of intergranular brittleness in metallic materials.

Inhibition of the intergranular brittleness of HR3C heat-resistant steel by strain-aging induced nano-M23C6 dispersion precipitation