normalizing/quenching/tempering/annealing... I'm kinda confused...

H

hammerface

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Mar 28, 2004
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Hi everyone - I'm reading all the posts I can on here and I'm reading Wayne Goddard's $50 Knife Shop and Blades Guide to Making Knives. I am going to be making knives via the stock removal methong and I am going to be using 01 and ATS34. I know I'll have to heat it just past non magnetic and quench appropriately and then temper immediately after.

My question is, when they refer to normalizing, heating it up and letting it air cool, does that only have to be done to steel which is forged for stabilizing the actual structure of the steel? I'm thinking that with using "ready-made" bar stock steel that I can skip that process, grind as desired, heat and quench and temper (3 times?).

I just started reading all the definitions and examples and I think I've thought myself into confusion when it probably isn't as confusing as I'm making it out to be. :o

Any clarification would be appreciated. :D
 
I do stock removal with 1084 and O1. Heat, quench and temper is all I normally do. I have seen some suggest that normalizing after grinding is a good thing. I am going to try that this next batch and see what difference there may be. With the ATS34 I can't help you, but somebody will chime in and give you some thoughts.
Rick
 
I can't tell you the answer, but I do know that it doesn't take all that much time to normalize steel. So the one time I've ever made a knife I did it three times before quenching, and I'll probably jsut keep doing it that way.
 
It's not required no normalize after grinding but it's a good idea. It'll relieve any strain in the blade form grinding and it'll also make the grain smaller, which makes the blade tougher.
 
OK - so shape and grind the blade as desired, then use a torch of some sort to heat blade to about 50 deg past non magnetic and then let air cool until it can be handled? (do what, 1, 2, 3 times?)

Then, heat to same just above non-magnetic, quench (once?)

Then, temper in oven at say 375-500 for about an hour and let cool off slowly in the oven (do this once?)

Sorry guys, there just seems to be SO many different methods out there that I'm having problems coming up with a method that I can write out as my "list of steps" for making each knife. I'd rather right out the steps ahead of time, ensure they are correct, and then start. Cause once you get into it a step could be missed and it's easier to erase a step on paper than backrack later on....
 
I use 0-1 and always normalize. Heat to non magnetic then let air cool. I will do this once or twice. after the second time in the forge I will take it to non magnetic then back in the forge for aprox 5 seconds then to quench. I temper 3 times. The first time at 400 degrees, the second at 375 and so on. Hope that helps. Your right, there are many different ways that people do but Normalizing is a step that cant hurt and usually helps. I would recomend Normalizing atleast once if not twice. Feel free to email me if I can help.

Shane
 
You can do a simple heat-treat with O1, but it will NOT work for ATS-34.

If you don't have the proper equipment (digitally controlled heat-source with ramping and soaking abilities, and liquid nitrogen) you'd be much better off to send the ATS-34 to Paul Bos. :)
 
i think a lot of the difference have to do with the equipment people have to work with, any given steel has a prefered sequence of heating treatments. but most all have a fairly wide range of effective heats , with a range of results. unless you have some pretty good test equipment your probably not going to be able to tell the difference between say a 56 rockwell, and a 60.
i figure if it ends up harder then a file ,,, well i hardly ever skin anything harder then that so it must be ok.
 
As Nick said,you can do simple steel alloys with a primitive HT setup.You will have to send your stainless alloys out for HT (ATS-34). I'll try to give you a simple explanation of the terms.This is for simple carbon steels (10XX, O-1)
Annealing - This is heating to critical temperature and cooling very slowly.Once it gets to the critical temp. place in a bucket of vermiculite and allow to cool overnight.It will convert the steel into its softest state.
Normalizing - After grinding,forging ,and any working of the steel there will be internal stress built up.Heating to critical and allowing to cool in the air several times releases these stresses and prevents warping upon quench.Heat to critical and set down on a fire brick to cool for about five minutes,best to repeat two more times.
Quenching - Heating to critical temperature (non-magnetic for simple steels) and rapidly cooling in the proper quenchant hardens the steel by converting the austentite formed at the critical temperature to martensite at room temperature.martensite is the desired hard steel for knives.Too fast a quench may crack the blade,so warm oil is the preferred quenchant for most blade steels.
Tempering - After quench the steel consists of un-tempered martensite, which is unstable (the action of the quench is still going on in the steel ),and will change structure.Heating to 350-400 will temper the martensite and make it stable.Temper in the kitchen oven at 350-400 for one hour, cool to room temp.,and temper again.A good thermometer in the oven is a good idea,since the dials may be off as much as 50 degrees.Tempering should be done immediately after quench .Quench,check with a file to make sure it got hard,clean off blade,bake in oven.If you leave it for a day,some of the martensite will have converted.

Hope this helps - Stacy
 
Thank you thank you!

That cleared everything up. I think in the best interest of the knife I will include normalizing as part of my process after all the grinding is finished. I will only try HT my own made from 01. The ATS34 and 440C I will take to a knifemaker that lives about 20 minutes away and uses and really accurate molten salt bath and does an excellent job.

Thanks again everyone! :D :thumbup:
 
Besides knowing the steps, you should learn the tests to see if they worked rather then just blindly doing them.

For the quench, there's the file test. Once the blade is cool enough to hold, try to file on the edge, if it bites at all then it's not hardened. If you suspect a good amount of decarb (which comes from an oxydizing atmosphere), you might want to grind it just a little before the file test since decarb leaves a thin skin of softer steel.

For tempering there's multiple versions of the brass rod test. It's more complex then the file test so I won't try to explain it right now. There's threads about it here and there's a couple of tutorials on peoples sites too.
 
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