Jump to content
I Forge Iron

Annealing VS Normalizing


Recommended Posts

Can someone help me understand the difference between annealing and normalizing carbon steel. From my understanding both require the stock to be heated to the critical temperature and then cooled slowly. As far as I know in both cases the particles realine and the lattice is refined yielding a soft workable piece. Is normalizing just only used the context before heat treating versus before further working?

Is their a difference and what is it? This may be a newbie question but maybe you guys can help me understand!

Thanks! Caintuckrifle

Link to comment
Share on other sites

It would be hard to beat Steves pind post for acurat and understandible. The brif senopsis is that aneiling is specificaly for making the steel as soft as posible, in simple carbon steels that is to heat it to above critical, let soke for a. very short time and to cool very slowly, usualy in an insulative medium such as wood ash. Normalisation is to reduce/relive stresses imparted by forging, welding or other process and starts again with heating to just above critical and then alowing the steel to cool slowly, still air is usualy suffcent for insulation. Simple carbon steel becomes non magnetic just above critical, but table salt melts at a just a hair above. Aloy steels may requre different mesures, usualy longer soak times, as do larger sections. 

Now this is just a thumb nail of Steves pined post, he has a lot more experiance with aloy steel, and thin sections, wich even in simple carbon steels may air quench or do other strangeness.

Link to comment
Share on other sites

  • 2 weeks later...
  • 3 months later...

My feed store sells horse shoes, they must know how to shoe a horse...

maybe not. 

Annealing is meant to get the steel as soft as possible, and can differ wildly from alloy to alloy, normalizing is to reduce induced stress in the steel, again this can differ from alloy to alloy.  Now annealing should anneal the steel, but normalizing usually wont fully anneal a piece of steel. 

See Steve I can read, lol

Link to comment
Share on other sites

Because they are slightly diferent operations to produce two diferent results.

the chemesstry acualy changes, or more persisly the molectular strucktur of the steel changes as its heated and cooled, the longer it is held at temp and the longer it takes to cool the greater that change. 

 

 

Anealing is ment to get the steel as soft as posible to make machining operations easer, such as drilling, filing etc. wile normalizing reduces stresses induced by forging that can cause warping and even cracking. 

Link to comment
Share on other sites

Can someone help me understand the difference between annealing and normalizing carbon steel. From my understanding both require the stock to be heated to the critical temperature and then cooled slowly. As far as I know in both cases the particles realine and the lattice is refined yielding a soft workable piece. Is normalizing just only used the context before heat treating versus before further working?

Is their a difference and what is it? This may be a newbie question but maybe you guys can help me understand!

Thanks! Caintuckrifle

The difference is the rate of cooling. normalizing= cooling in still air. annealing= cooling in dry wood ash or vermiculite.

Link to comment
Share on other sites

As you suspect and Charles points out, "everyday" steels work with these rules of thumb. The full answer is: to properly work your steel, read the datasheet and follow the instructions. For high-alloy steels, cooling in still air might harden and cooling in vermiculite might not even result in normalization.

Link to comment
Share on other sites

  • 1 month later...

Annealing and normalizing are not the same.

 

A way to think of the heat treating process is that to reach a fully hardened state,  you must start from a fully annealed state. Annealing brings you down to max softness, a ground zero. Hardening does the opposite. If you are not at "ground zero, all else will not apply. All this is my paraphrase from Turley Forge many moons ago. I recently had this verified in a good book called " Metalurgy of steel for bladesmiths and others who heat treat and Forge steel" by John D Verhover. He states that all the data in the stats sheets and phase change charts and graphs are based on a fully annealed piece of steel. 

 

I believe the reason that many knife makers have this notion that anneal is not needed or is the same as normalizing is because they tend to start out doing stock removal from steel bought from a supplier. Since all tool steel purchased comes fully annealed, there is no reason to anneal again after stock removal . They can go straight to hardening. Again from Turley Forge, stock removal can stress the steel especially if you remove a lot of material. He recommended annealing anyway. So it is part of my routine.

We blacksmiths most often may start with annealed steel but once it's brought up past critical to a forging heat (bright orange to yellow) the structure is changed (at critical) and must be annealed as part of the HT process.

 

 

A great and simple test to show the importance of annealing over "just normalizing" is to make two simple tools you use a lot. Centerpunch, small cold chisel, scribe are examples in my shop. Just normalize, harden, temper one and anneal, harden, temper the other. Use them equally and see how long it takes to lose yer edge.

 

I've never been much for normalizing as part of my HT process, but all my tool steel drop is air cooled after use to make sure I don't end up with a hardened end that would dull my tools otherwise when used again. I don't use air hardening steels by the way.

However I'm reevaluating the importance of "refined grain structure" in my tools. This is the primary importance of normalizing. Even if it makes a "better" product, the difference may not be noticeable for the tooling we do. If we were doing springs for the space shuttle, that might be different. However the time to normalize is minimal.

 

Note! Any differences between what Frank attempted to hammer into my head and what actually got there are my responsibility,,, no one else's.   ;)

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...