Posted by lee on September 03, 2009 at 11:44:05:
In Reply to: Re: Surface damage on hard cut gears posted by Ivan Doretzkiy on August 28, 2009 at 23:54:07:
Ivan
one of the reasons or probable cause is the gears are being carburized with a carbon content higher than .95%, thus causing very hard gears, 70 HRc or harder at the surface.
second one is "even with grinding" carburized gears must be monitored with nital etch. must make sure there is no tempering or rehardening of the carburized surfaces, which is not a good thing.
I also suspect the feeds and speeds are too aggressive. which is tempering the gears.