help with definitions please

[strahd71]

i was wondering if some of you would be willing to simply explain normalizing and anealing. and what the difference is. also steps to do both would be great.

thanks

jake

 

[WalterDavis]

Jake, normalizing is heating steel to a certain temperature (or a series of temperatures) and following that by air cooling. It relieves the stresses cause by forging or grinding by 'normalizing' the metal's internal structure. Otherwise you have spots in the blade that have been heated to different temps and the cooled at different rates.

Annealing is putting the steel you are working into a softer state for easier machining.

Following the "Knivesby" link in the newbies thread I found this page on Kevin Cashen's site http://www.knivesby.com/knifemaking-Kevin-Cashen-treating-1084.html that should give you an idea of how normalizing/annealing fit into the process of making a knife

Edited to add: The exact temps and processes that you would want to follow would depend on the steel you're working on. Some steels don't need or want to be normalized prior to heat treating.

 

[Whoever Wherever]

Jake to normalize I heat to non magnetic and allow to cool to black, usually 3 times. done before heat treat to standardize the structure of the steel like Walter said.

To aneal I usually usually heat to non magnetic and stick it in vermiculite ( get at lawn and garden store) to cool slowly. Again as Walter said this "softens" the metal.

There is more to it than that of course, but that's the basics of it. If you get a specific steel then people could chime in about what temp to use for annealing and normalizing. Using nonmagnetic is not the scientific way to do things and isn't a good indicator on all steels if I am correct.

 

[mete]

Just heating to non-magnetic is not enough .Hardening typically is 75-100 F above magnetic. The industrial definitions are ;
Annealing - 50-100 F above the critical temperature and slow cool in the furnace , ashes or vermiculite.Structure - usually spheroidized or coarse pearlite .
Normalize - 100 F above critical and cool in air.Air hardening steels are not normalized as it would harden them. Structure pearlite.
Knife makers definition of normalize includes heating just above critical ,air cooling and repeating usually three times to produce a smaller grain size.

 

[strahd71]

thanks guys!

i understand it better now,

walter that link was good, thanks

jake

 

[WalterDavis]

:thumbup: No problem. There's so stinkin' much info out there that it's sometimes hard to wade through it all. I just found that one last week, going through all the heat-treat info looking for info on quench oils

 

[Whoever Wherever]

Just heating to non-magnetic is not enough .Hardening typically is 75-100 F above magnetic. The industrial definitions are ;
Annealing - 50-100 F above the critical temperature and slow cool in the furnace , ashes or vermiculite.Structure - usually spheroidized or coarse pearlite .
Normalize - 100 F above critical and cool in air.Air hardening steels are not normalized as it would harden them. Structure pearlite.
Knife makers definition of normalize includes heating just above critical ,air cooling and repeating usually three times to produce a smaller grain size.

Thanks for clarifying this Mete. I forgot to mention that with my forge I am assured to get at least a 100 over due to lack of finer control. Something I need to address asap.

 

[strahd71]

walter,

your so right there is alot of info. i wish some one would could/would really compile all the information on this forum. i dont know if its really possible just because of the amount of info.

jake