Normalizing and Annealing

Joined
Mar 14, 2000
Messages
509
I realize that normalizing helps to relieve internal stresses caused by shaping the steel during forging. Besides making the steel softer so that I can grind and shape it prior to quenching, is there something else that annealing accomplishes that is important as far as future performance of the blade is concerned? Does the steel have to be put back into a ferrite/cementite structure through annealing in order for the quenching process to be able to fully transform austinite to martensite? Are there other benefits?

Rick
 
Only a few steels benefit from anealing(5160 and 52100 that Im sure of).
For simpler steels its a complete waste of time.
Thoroughly normalizing softens steel up about as much AND has good effects on grain and grain formation.
So the time spent letting a blade anneal, could have been spent doing a whole bunch more beneficial normalizations.

Joe Renner
 
Thanks for the input Joe. I am using 5160. I did about 5 normalizing cycles during the forging process and I just completed 3 more cycles (post forging). Now I'm doing the annealing cycles. Since this is my first forged blade and also the first blade that I will be doing my own heat treatment, I'm planning on doing triple normalizing, triple annealing, triple quenching and triple tempering with a deep freeze cycle prior to the last tempering cycle. This is going to be the knife that I use as a standard for future testing. Hope it works out OK, it should with all of the good advice from everyone here. Thanks all!

Rick
 
Does the steel have to be put back into a ferrite/cementite structure through annealing in order for the quenching process to be able to fully transform austinite to martensite?

No. That depends on quench rates to get your martensite to transform from austenite.

Annealing won't necessarily provide you with any huge future benefit (end function wise) in your blade except to relieve stress as normalizing does (in 10xx that is). The primary purpose of annealing is to soften a steel for grinding and/or cold fabrication. Your structure will be more stress free and typically a bit easier to grind though. In many alloy steels, you must if you plan on grinding. However, the stress issue will be negated when its time to harden and temper and most of that topic is kissed goodbye. Multiple normalized or fully annealed.

My system is to forge; then cycle above and below critical 2 or three times, then again above Ac1 and let air cool (normalize) in the areas I forge. The blade is then fully annealed, 10xx or not; then ground; then hardened, then tempered. Works fine for me.

I will say it again... grain size is dependant upon prior austenite size.

Jason
 
Originally posted by Epsilon


I will say it again... grain size is dependant upon prior austenite size.

Jason
Myself and many other pros have found that this doesnt have to be the case.
I dont know why(only a few do I think), and I dont want to, Id rather just accept it. More ya know less you want to syndrome, I guess.
 
Back
Top