Some light:
During the bleaching process the silver isnīt converted to another metal, it
is only converted to itīs oxidized form. We do have Ag+-Ions in the bleached
form and Ag-zero (silver-metal) in the fixed print. The need for fixing on
an unbleached or bleached print arises in the low stability of silver-ions
against air, irradiation and so on.
You should fix your prints, otherwise they will turn grey after a short
period of time.