Have the pipes been used on the bike as chroming used pipes will end up cracking as chrome will weaken the old pipes, if the pipes have been made and not used and haven't had any chrome on them before will be fine, most good chrome shops will shy off doing old used pipes, I worked as a chromer after I left school, we had a few motorcycle exhaust shops send them there new pipes to be chromed as well when I got my headers made for my Norton they were chromed by the same place that I worked at many years before, I still have these headers on my Norton after 33 years use and are still good for their age, but once I made the mistake to chrome my dirt bike exhaust pipe (old used pipe) after a few weeks they started to crack around the welds.
I think the problem with old pipes is the carbon that is inside the pipe, maybe getting them sandblaster inside mite help before chroming but there would not be no garrenteed after, a lot of good chroming shops are closing because of the cost to buy the metals that are used in the proccess as well the chemicals that are used as well power cost to run the tanks.
Ashley