Microstructural evolution in a new Fe based ODS alloy processed by mechanical alloying

• Optimal milling time was chosen for 50 h which is proposed.
• The steady state means a balance between increase in dislocation density and dynamic recovery.
• TEM observation revealed that the grain size of milled powders was maintained in the nanoscale range.

Oxide dispersion strengthened (ODS) ferritic steels containing a high density of nanoscale clusters are produced by mechanical milling show excellent properties such as good irradiation swelling resistance and high-temperature creep strength. Mechanical milling with the aim of a fine dispersion of oxides dissolves in the matrix. The influences of process parameters during mechanical milling of ODS ferritic steels are important for material properties. In this research we investigated different milling time for the morphology and properties of powders. The results show that the powders by a stainless steel grinding media are experienced three stages: the mean powder size increases firstly then decreases. With the extending of the milling time, the mean powder size increases again. Otherwise the grain size decreases initially and then reach a saturation value. The grain size of milled powders was maintained in nanoscale range by TEM observation.