Ordering a crank from autozone..

[suprarich]

You're a good sport rich . Not to be picky but I believe ammonia gas is usually used in nitriding. At least that's the process I'm familiar with.

I believe the heat treaters here use an ammonia type chemical in the salt bath style hardening. They used to call it melaniting, but I believe the term was trade marked by another company. Now everyone has a different name for salt bath style. One thing I like about it is it tends not to bend the cranks as much as the nitriding oven. One bad thing is that the penetration is only about .003. So we can not grind the cranks after treatment. With 60 hr nitride furnace, we can still grind the crank since the penetration is about .012-.013.

IJ - sorry if I had my terms mixed up, us old hicktown boys don't always know left from right. I should have said annealing from the begining.

 

[3p141592654]

Induction hardening is a form of heat treatment in which a metal part is heated inductively and then quenched.

The quenched metal becomes harder. The inductive heating limits the depth of the hardening, without affecting the properties of the core.

To my knowledge this technique does not use any external gases or baths. The processes discussed above using ammonia (urine back in the day) are nitride hardening which is something different from inductive hardening.

All of this is not to be confused with flame broiled hardening, which is some magical process at Burger King to turn meat into carbon.

 

[IJ.]

Rich: "Stress relieving" maybe?

"Annealing" is softening a material to it's base state ie: removing hardness so it can be machined.

 

[suprarich]

Rich: "Stress relieving" maybe?

"Annealing" is softening a material to it's base state ie: removing hardness so it can be machined.

IJ - yes, I posted that a few ago about stress relieving. Each side of the rod journal where the machined portion meets the non-machined is hit with a little higher oxygen flame to stress relieve the crank after grinding. Cranks that have had this done will have the blueing proof on the non-machined portion. We call it annealing, but is not a true annealing. Not like annealing sheet metal with low oxygen flame to soften it up. We do this also to staighten a slightly bent crank too. A little heat at the right time in the right place will pull a crank straight again.


Jetlock - I know what kind of Nitriding you are speaking of, but we don't use that method any longer since ion-plasma nitride method came to town. It uses nitrogen with a little hydrogen at a lower temp then conventional furnace gas nitriding. Little to no bending of the item being treated. Shorter treatment time and deeper penetration. The peice is used as a cathode and the furnace itself is the anode. they run a dc current pulse to the piece causing the nitrogen to be absorbed at a faster rate than in a conventional method.

 

[mk3ftMFw]

thanks for the info, i just gotta find someone that isnt trying to play a 20 year old and charge him a grand to get his crank machined.