I can't find anything specific in the documentation. The step_id value is an INT though, so that implies a limit there. However, I sure wouldn't suggest you create a job with that many steps. I'd guess if you've got over 50 something is wrong. Most jobs I've created had no more than 10 steps.
"The credit belongs to the man who is actually in the arena, whose face is marred by dust and sweat and blood" - Theodore Roosevelt