Need Help Is My Heat Treat Plan Right??

S

secor c1

Member
hey guys this is my first post on this forum...please excuse the spelling and grammer its bad to begin with but i have had a very long day followed by ALOT of reading on this heat treating subject. Any way i have just created my first damascus blade wich is also my first blade in a gas forge so it is not the best. and i am new to knife making all togather as i only made 2 blades before out of old files and one out of 1080 on a coal forge. now i am at the point to heat treat this blade and as i said i have been reading alot i am in a lil bit of information overload lol no a lota bit. so i would apreciate if i lay down the steps as simply as i can and if some one can help and just let me know if this is wrong....

NORMALIZING- 1st step...(this i already did but now reading something i might have done it wrong conflicting info so first what i did) i heated blade to non magnetic took it out let it cool in still air to room temp, then i heated again and again let it cool to room temp, and one more time......now the conflicting info says not to let it cool to room temp. but to heat to non magnetic and take it out of forge for only a second or 2 just till the color leaves and as soon as it turns black it goes back in and repete 2 more times..........so whats right cool to room temp between heats or only till black? maybe either works?

HARDENING- with 1080 these steps (hardening and temper seem straight foward) heat a lil past non magnetic and quench in canola oil since i dont have any special quench's

TEMPERING- heat in oven at 400 for 2 hours let cool to room temp and do it again.

are you suposed to clean the blade in between each step? between normalizing and harden do you sand it nice and shiny again? obviously clean the quenching oil off but do you clean/sand between hardening and tempering?

THANKS to any one that can help i have read soooo much tonight i am seeing double...nah triple i just wanna make sure i get this right or at least close to right hopefully i get this figured out and can procede tomorow thanks again to any one offering help i really appreciate it!! now it time for bed
 
Normalizing- many bladesmiths* are rather confused about normalizing, what it is and what it does. What normalizing is for is given right in its name- it is to bring the internal condition back to normal, but more accurately it is for homogenizing. This can apply to grain size, carbide condition and strain effects. Actual normalizing must occur in temps that achieve total solution to accomplish these goals (>Ac3 or AcCm), but with 1080 this would be very low, at the eutectoid, so it is best to heat a little more for a full reset. 1500F will do, and your non- magnetic state will be in the ball park.

The most critical part of normalizing is not however how hot you get the steel, but rather how evenly you heat it and cool it, and the rate at which it cools. Cooling should be the rate achieved in still, room temperature, air, no faster and no slower. What temp you cool to is up to debate depending on what you are more concerned with fixing in the steel. Regardless of the goal you must at least cool until the magnet is sticking again to accomplish anything. It is at this point that a new phase is formed from which to move on to the next cycle; without this you are just reheating the same phase, accomplishing nothing, or even making things worse. If you are focused on normalizing for the sake of eliminating stress related issues that could lead to subsequent distortion then you will want to allow the steel to cool until you can hold it in your bare hands. Cycling the steel to temps lower than full solution temp, or cooling at rates other than evenly air cooling can be called thermal cycles but cannot accurately be called “normalizing”.

I am very often seeing extreme times with multiple cycles recommended by knifemakers these days, and you seem to have gotten some of this input. Two hours is the total required for tempering, two cycles of 2 hours, totaling 4 hours, is rather extreme and overkill for the task at hand. 400F may or may not be appropriate for your goals. Is the knife going to be less than 8” in length or over 8” in length? If it is a larger knife that will chop or cleave then 400F or better may work out well, but if it is smaller fine cutting knife then 375F-400F would be a better range, particularly for 1080 which will only have the martensitic hardness with no carbide action to support the edge stability.

Leaving normalizing scale on the piece for hardening will result in increased distortion and inhomogenous hardening, it does not have to be polished but it should be cleaned down to bare metal for the hardening. Shiny metal can be helpful during tempering to see that oxidizing (heat color) temperatures have been achieved, although I highly recommend following your thermometer and not those rather deceitful colors to gage exact temperature.

*I do not use the terms “bladesmith” and “knifemaker” interchangeably. A knifemaker is anybody who makes knives. A bladesmith is one who forges knives to shape, and often come up with interesting definitions of their own for heat treating concepts, while many other knifemakers follow industry specs and literature and thus the more accurate definitions.
 
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Kevin, Thanks alot man it really helps clears up almost everything just to see if i got it right with what you were saying about normalizing is that either letting cool till black or letting cool to room temp or i think you said "till you can hold in your hands" both will work but letting cool till room temp will work better for reliving stress right? lastly am i right to assume that since you didnt touch on hardening that do what i said "heat lil past non magnetic and quench in canola oil " is sufficient
 
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