This question pertains to parts from a burned machine. How hot does a gear have to get to change its temper? I have seen gears that have gotton so hot the metal turns blue and they would be consisdered scrap. If they have only darkened like a cast iron pot, would that change the temper? The gear I am speaking of got hot but remained submerged in oil through out the fire. As you can tell I am having doubts about using this piece, but the new one is almost three grand. Anybody with experience with a situation such as this?
the first got hot, the second did not.
the pics need to be larger guess not
If it remained in oil, there is no way it could get hot enough to weaken the temper or make the metal brittle for wear. Actually, that is how they temper steel. In oil.