I knew this sounded familiar. There is a phenomena called "Hydrogen Embrittlement" that can be caused in some cases by chrome plating steel.
I did a quick search on google using "chrome hydrogen embrittlement" and found many links including:
http://www.nmfrc.org/crarchive/feb02a.cfm http://www.finishing.com/1600-1799/1747.html http://www.nhra.com/dragster/1999/is...echnology.html