Co-precipitation mechanism of Cu-rich phase and κ-carbide precipitates in Fe-28Mn-10Al-1C-3Cu austenitic low-density steel

The excellent comprehensive properties of Fe-28Mn-10Al-1C-3Cu austenitic low-density steel are related to its main precipitates of Cu-rich phase and kappa-carbide particles. The co-precipitation mechanism of Cu-rich phase and kappa-carbide particles in Fe-28Mn-10Al-1C-3Cu austenitic low-density steel are investigated. Adding Cu to Fe-28Mn10Al-1C austenitic low-density steel can promote the precipitation of kappa-carbide. The kappa-carbide can also promote the precipitation of Cu-rich phase with FCC structure. The kappa-carbide preferentially precipitate compared to Curich phase. The kappa-carbide and Cu-rich phase have a cube-on-cube orientation relationship with the austenitic matrix: [110]gamma//[1 1 0]kappa//[1 1 0]Cu and (1 1 1)gamma//(1 1 1)kappa//(1 1 1)Cu.