Burn To Red the Steel questions

[Nasgul]

Hello Spyders :spyder:

I wonder what it will do to the steel (hardness/flexibility) if I burn to red small part (screw, clip, ...) ?
Will that be ok ?

I already did it on a wire clip, it look nice.
Ok, ok I'm asking questions after the try... :D

It also could be nice on the blade.
But I think blade received heat treatment so it could change the performance of the blade ?

(Sorry but English is not my own language, so, I hope I'm clear enough, if not, let me know.)

Thank you in advance for your help.

[bdblue]

In general if you heat the steel to red hot and let it cool slowly, the steel will change to its softest state. You would not want to do this to a blade and probably not to a clip. If you heat steel with the proper alloy to red hot and cool it very rapidly, it will become very hard. A normal heat treat for a knife blade is a combination of these things to get the steel to the correct hardness level.
Depending on the alloy, heating steel to red hot and letting it cool will oxidize the top layer of the steel which in the worst case puts a layer of scale on top of the steel.

[Nasgul]

Thank you for your answer bdblue ! :)

Just the last part that I'm not sure to have understood well.
As I said, I already did it to a clip... it's just a clip so no problem if I make something wrong...
After burning to red and let it cool slowly, it gave a dark red blue burnish color to the clip, is it what you mean by "oxidize" ?

So, if I heat it to red hot and cool it very rapidly, will that be ok for the clip and screw ? and will it keep the color I was writing just above ?

[noseoil]

Heating to a "red" hot will soften the steel. All of the steel becomes one state and will be "soft" if allowed to cool slowly.

If the red-hot steel is "quenched" in water or oil, it will become very hard, but can break like a water glass, too hard, not tough, brittle.

If it is heated again, but just a little bit, not to red-hot, then allowed to cool slowly, it will stay hard but will not break like a glass.

There are many more things which can affect the steel, the hardness & other things, but this is usually how steel is made and then treated to become different for many uses.

[Nasgul]

Thanks for your reply noseoil ! :)
So I'll have to do it again, and cool it slowly...
I'll be few days away, I'll try to let you know and show you when I come back...
I take the bad treated clip with me, on a knife of course... ^^

[noseoil]

If you can find some information in an internet search in your regular language, it might be easier to understand. There is a lot of interesting information about how steel is hardened and how this affects the use of each type of steel. Good luck with your search!

[defenestrate]

I seem to recall coming across a famous classic French text on working steel, Nasgul, but I can't seem to find it now. You will probably want to look up transformation temperature, quenching, tempering and annealing to understand some of the basic processes in heat treatment of steel.

If you let that steel you got red hot cool slowly, it probably will not break too terribly easily, but may easily bend out of shape. IIRC, the clips on salt series knives are titanium, but most of the others are a fairly mild stainless steel, maybe like a 300-series (I could have sworn Sal discussed this once but I could be wrong). If you aren't too hard on your clip, it may be okay. As far as the screws go, I would be more concerned about damaging them with heat treating them differently as those threads, of overly softened, will probably strip easily.

[Nasgul]

defenestrate (funny pseudo^^) and noseoil thank you for your help ! :)

Yes, I should have search in Enlglish but it seems I prefer to do it in the hardest way. It help me pratice, and as I do it on :spyder: Spyderco, you are more aware of all usefull informations. And the last part, it help me to pratice my english ^^

defenestrate, if you find back the French text, let me know :)