Not if you stick with a stock voltage overclock. Overclocking typically produces more heat, which causes more damage in the long term, but gts450's run so cool you don't have to worry at all.
Typically on stock volts you should be able to get atleast 900 core clock and 2000 memory clock quite easily and fully stable for 24/7 usage.
Adding extra voltage for an overclock can shorten the lifespan, but honestly by the time it would kill the card it will probably be so outdated it belongs in the garbage can anyway.
Whats the rest of your setup? You should fill out your signature with your system
By the way,for future reference theres one other thing, you posted this in the CPU section....this would belong in the video card section. You were most likely confused because it says ''overclocking'', but it's refering to CPU overclocking
By the way,for future reference theres one other thing, you posted this in the CPU section....this would belong in the video card section. You were most likely confused because it says ''overclocking'', but it's refering to CPU overclocking