Annealing Steel

If you are grinding it from a piece of flat bar it was probably annealed when you received it.
 
Not necessary. I would suggest you read the stickies. It sounds like you haven't much back ground info and these will give you are real boost. The best on your knife ! Frank
 
Annealing is pretty simple for basic carbon steels, but most other steels have more complex annealing requirements. Steel usually comes annealed.
Stress relief is usually done post forging, but some do it after heavy grinding. It releases any built up stress in the steel, but does not greatly change the structure or grain size.
Normalizing is done pre-HT to get the steel and its grain structure ready for hardening. Again, that is more important if the steel was forged.

Grind/file/sand the blade to get all the things you want done before hardening, and leave just a little too take off after HT. I usually say to take the blade to about 95% done. The surface should be smooth and have no dings or scratches, and be at 220 to 400 grit finish. The edge should be about .020-.030" wide for carbon steel, and .010-.020" wide for stainless. Make sure high alloy steels are completely smooth and flat before HT, because sanding them after HT is really, really tough.
 
bladsmth said:
Annealing is pretty simple for basic carbon steels, but most other steels have more complex annealing requirements. Steel usually comes annealed.
Stress relief is usually done post forging, but some do it after heavy grinding. It releases any built up stress in the steel, but does not greatly change the structure or grain size.
Normalizing is done pre-HT to get the steel and its grain structure ready for hardening. Again, that is more important if the steel was forged.
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I am hoping that you got the terms mixed up, Stacy... or I am off on my info. Normalization(not stress relieving) is usually done after forging.

Stress Relieving is done at a lower temperatures(below critical) to relieve strain/stress. This process wouldn't be adequate to fix the majority of "bad things" we do while forging. It is great for taking care of the bad things we do with grinding, straightening, etc...

Normalization involves bringing the steel up past critical in order to recrystallize. When done in cycles with reducing heats, it can refine grain(and most definitely relieve stress). Perfect for after forging.
 
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I run stress relief along with normalizing cycles after forging or shaping and bending. Its one of the set programs on my electric kiln. For something like 01 its one hour at 1200 ramp to 1600, hold ten minutes, cool to black, ramp to 1550, cool to black, ramp to 1500 cool to black. The hoped for result is steel with little stress and a very refined grain structure.
 
Interesting, Fred... What is the reasoning behind stress relieving prior to normalizing?

ETA:

I completely understand the purpose of running a SR cycle prior to heat treat. It makes sense, considering the possible stresses we induce by grinding, straightening and such. I just can't wrap my head around its benefit for a rough forged blade, soon to be normalized/thermal cycled. It seems to be an redundant step... but it wouldn't be the first time I was wrong.:p
 
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Fred.Rowe said:
I run stress relief along with normalizing cycles after forging or shaping and bending. Its one of the set programs on my electric kiln. For something like 01 its one hour at 1200 ramp to 1600, hold ten minutes, cool to black, ramp to 1550, cool to black, ramp to 1500 cool to black. The hoped for result is steel with little stress and a very refined grain structure.
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Something else, if you don't mind(and I'm not drifting too much)...

You are cooling to black after your heats. Is it a slow cool? Wouldn't that leave you with a predominantly coarse pearlite structure(as well as a few other precipitates that I admittedly know little about :o)? Would it not make more sense to quench on that final 1500F cycle and perform a subcritical anneal cycle(spheroidizing), from a predominantly martensitic structure?
 
So it sounds to me that with stock removal blades normalizing is not necessary, but annealing, or stress relieving is beneficial after heavy grinding. Am I right? Thanks for all the great info guys!:D
 
Morning Rick!

It was making the bevel grinding clamps that got me doing this. It was recommended by the mill to do the stress relief followed by normalizing cycles. I had problems with the clamps snapping, I contacted the company and they e-mailed me a sheet giving me their recommendations. The clamps I make are stressed out , so to speak, after I heat the center section and bend them into a "U" shape. I have had no clamps break since I've started running these cycles.
I cool it fairly fast, not leaving it in the oven. I do quench from the 1500 temp not let it go to black on the last heat. Would you tell me why you are spheroidizing after grain reduction? Would you not go to quenching after normalizing? When I forge blades I am constantly cycling the steel as its being forged and reduced to blade shape. If its damascus I do stress relief after forging; I rarely anneal unless needed to drill and then normalize two or three times before hardening. I make a lot of long blades and my main concern is keeping the warp factor down as much as I can. There are many ways to get there this is the one I use.
Have a good one; is it springtime up your way? Fred
 
Fred, Spring has just begun around here. :thumbup:

I think you normalize after working/tooling, just before HT?... I don't. After forging, I normalize 3 times, quench, then spheroidize from 1250F. The grain is refined and in its softest state. I shape, drill, etc... and perform a 1200F stress relief cycle prior to final HT. I still can't think of the metallurgical reasoning behind SR after forging if you intend to thermal cycle before quenching, anyway.

I think your clamps are a different story, Fred. You drill, tap and grind them prior to the bend... so it is safe to say that the most stressful state is after the bend, just prior to HT. I would definitely normalize before the quench. What was your process prior to talking to the mill? What metallurgical reason did the mill give you?

If I straighten after forging and grind properly, I should be inducing very little stress prior to HT. The SR cycle is just added insurance.
 
Rick Marchand said:
Fred, Spring has just begun around here. :thumbup:

I think you normalize after working/tooling, just before HT?... I don't. After forging, I normalize 3 times, quench, then spheroidize from 1250F. The grain is refined and in its softest state. I shape, drill, etc... and perform a 1200F stress relief cycle prior to final HT. I still can't think of the metallurgical reasoning behind SR after forging if you intend to thermal cycle before quenching, anyway.

I think your clamps are a different story, Fred. You drill, tap and grind them prior to the bend... so it is safe to say that the most stressful state is after the bend, just prior to HT. I would definitely normalize before the quench. What was your process prior to talking to the mill? What metallurgical reason did the mill give you?

If I straighten after forging and grind properly, I should be inducing very little stress prior to HT. The SR cycle is just added insurance.
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They didn't give a reason; just try this and see; so when it worked I was thrilled and have done it ever since. Two and a half years with no broken ones so it has a track record. Keep in mind I have my big Fisher anvil aligned with the earths magnetic poles; what does that say about me. :rolleyes: Good to hear theres sunshine up your way.

Regards, Fred
 
Rick,
I relieve stress when I am done with the work for the day, and will be doing more work. I normalize before HT to get the grain structure and carbides ready for hardening. It would be unnecessary to normalize after each forging session unless you suspect some severe damage was done to the steel structure.
I stress relieve by heating to a dull red and letting bit cool to black, quench and repeat. Normalization is done by the standard three descending cycle method.
 
That is because you are closer to the north pole. It won't work in the lower latitudes. BTW, did you have to learn Gaelic to move to NS.
 
bladsmth said:
That is because you are closer to the north pole. It won't work in the lower latitudes. BTW, did you have to learn Gaelic to move to NS.
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I was going to ask that, but thought it too forward a question. I want to know if snow shoes are standard issue that far north. Good One!
 
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