The effect of addition of minor elements of Cu and Cr on precipitation in this alloys has been investigated by hardness measurement, tensile test and transmission electron microscopy (TEM) in this study. Precipitates have been observed by conventional and high-resolution TEM (HRTEM), and the precipitation sequence of this alloy contained Cu or Cr is proposed. In samples aged at 523 K for 24 ks, we could find out remarkable difference of precipitates in these alloys.