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Can you normalize too much?


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I understand why we normalize, and I always thought that normalizing does reduce hardenability. The reduced hardenability would only be a factor if you over normalize. I was told I was wrong which is fine...but why? I can't find anything on the topic. Thanks everyone.

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"Hardness is a function of the elements in the alloy and the quenching and following tempering temperatures. "Normalizing"  takes place before any pre-quench heat treat cycles (which serve to refine the grain and structure)

Normalizing basically occurs to various degrees in the forging process itself. The point of a deliberate cycle of normalizing is to make it uniform throughout the piece.

With the heat treat cycles ahead of a normalizing cycle I can't see how it would affect those heats or the content if the alloy.

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With a shallow-hardening steel like 1095, W1/2, and very low manganese, it is possible to get the grain so fine it's impossible to quench fast enough to harden.  This is in the realm of 12 or 15 back-to-back cycles.  If you do any hot work in between it's easy enough to grow the grain back, although the vanadium in W2 slows grain growth quite a bit.  It's not something you really have to worry about as far as hardenability under normal circumstances, but by the time you do that many cycles you will have alloy banding becoming more of an issue. Then you have to do a long soak to redissolve the carbides, which also results in grain growth.  Then you're back where you started.

If you're using a deep-hardening steel, alloy banding is really the only issue. Again, though, we're talking a LOT of thermal cycling before that happens.  What is your steel and what is your issue?

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I was just having a conversation about why we only normalize three times. I know why I do it. My three descending cycles set me up to make nice hamons ( I use 1075, W-1, and W-2 steels 99.99999999% of the time). It also seems to make my grains very nice and fine when I work 80crv2. I am lazy, and I didn't have to change any settings on my HT oven for my normalization cycles when I want to change over to 80crv2. That's why I do it. The person I was discussing this with said there was no way to over normalize steel, you could do it as many as you wanted, and the steel would harden. The reason we don't do it any more than three is there was no point. After three times the steel gained no more benefits, because the grains were as fine as they could get. This made since to me, but I could have sworn that a long time ago I think it was Kevin Cashen (memory has become an issue after an incident) circa 2005, said that too many nomalizations can lead to it becoming difficult to harden. Of course in the discussion I had completely forgotten about alloy banding. Are there any charts I can look at regarding this normalization not hardening phenomenon? It has been crazy trying to find anything online.

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Thanks! I'm pretty sure that is where I read the info was that thread. Thank you. The last post of Kevin's on the first page is what I seem to remember.

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