likely?? no. but, it's worth a try i guess. 600 watts is a pretty big increase over 450 watts, and that's what i have. (technically, yours is less than half as powerful though, because mine has two 12v rails at 22a, yours has a single one at 18a).
what type of cpu are you running, and what are the rest of your system specs? you see i run 3 hard drives, two ram modules, 4 processors, an HD 4850, and like 10 million LED fans. these things are useful when calculating psu requirements. i also plan to run dual HD 4850's soon enough, my power supply should hold out though.