burn marks...

L

laCie

Joined
Jun 23, 2005
Messages
374
i recently exposed the tip of my edc minis socom elite to fire... and the tip is now discolored... is this permanent ? or is there a way to get it off ?

regards

Lem
 
Not gonna ask how that happened, but how long was it there, what kind of fire was it, and what sort of discoloration are we talking here. There's little likelyhood the heat treat was messed up, assuming it wasn't left in the fire for a long time, the stainless steels used for that folder are generally tempered at very high temps, and it does take a while for the steel to heat up. If it's just black carbon soot then wipe it off with a damp rag or something, light gold you're still okay, if the steel has turned a shade of blue or purple then you may have something to worry about in regards to softening, but you'd have to ask someone that actually knows about how that particular steel responds to high temperatures.
 
yeah its a light gold/yellow... im soaking the tip in militec hoping that it'll somehow take the discoloration off... is this wishful thinking ?

Lem
 
i dont know if i would recommend this to anyone but oven cleaner has taken the discoloration off... i'll keep you guys posted on if the tip melts off any time soon though...


lem
 
A light gold/yellow shouldn't have affected the heat treat too much, if at all. It's when it turns blue that you know it's ruined.
 
laCie said:
yeah its a light gold/yellow... im soaking the tip in militec hoping that it'll somehow take the discoloration off... is this wishful thinking ?

Lem
Click to expand...

Yep. :p

Lem, the color is an oxide film that has formed on the surface of the steel. To get rid of it you need to mechanically remove that film of oxidised steel. So you need need some kind of abrasive. It can be a very gentle one, but you will have to wear this stuff off, not dissolve it. (As far as I know, anyway.)

Sandpaper, scotchbrite, steel wool, buffing wheel, metal polish (and elbow grease), toothpaste, etc.

Not the end of the world.
 
Planterz said:
A light gold/yellow shouldn't have affected the heat treat too much, if at all. It's when it turns blue that you know it's ruined.
Click to expand...

With simple steels (Carbon, 400 series, etc) but certainly not with M2, and most of the high alloy steels - ATS34/154CM, etc - have stable temper well past blue.

It's still a good rule of thumb to never get a knife hot enough to blue, of course.
 
Test the tip a little: stab wood and pry with it (lightly!) and check if it rolls easily. If it does, it affected the temper.
 
I recommend one of those green scrubby pads that you use in the kitchen sink. A little elbo grease, as mentioned above, and you should be good to go.

D2
 
The hardening stage of heat treat is done at very high temps. The tempering cycle is generally more like 400 degrees. If you got it hot enough to change color at all, you might well affect the heat treat but the knife might well still be useable, just not hold an edge the same as if it were factory treated. If you get it to turn blue, you most likely burned the carbon away and ruined the steel.
 
Blue isn't quite enough to burn away carbon, and ATS34/154CM/most other high alloy stainlesses generally temper above 800F, well past the blue color.
 
Before you try a harsher abrasive , you may want to try some Flitz.
Apply , let it sit and polish off , try it a few times. May work for you without scratching the blade.
 
Yoda, you should check your facts. I might be wrong about burning off carbon at blue, but you can certainly affect HT if heating above the draw temp.

According to the heat treat recipe for 154CM posted on Crucible's website, the Austentizing temp should be between 1900f and 2000f. The temper should be two cycles of between 400f - 1200f, but tempering in the 800f-1100f range will cause a sensitization which will cause a slight loss of corrosian resistance and toughness. "We recommend this tempering range be avoided" (exact quote).

You can read more about their fine knife steels here:

http://www.crucibleservice.com/products/knife/index.cfm
 
Yeah, I knew there was a high and low range for tempering, just wasn't sure what the ranges were. I was under the impression 800 was within the low range. I still hold that drawing it to a blue color will not burn carbon :foot: The point was that heating it to blue or much higher up to 800 degrees is not likely to affect the hardness of the knife, and I seriously doubt the time involved here would be enough to cause the loss of toughness that Crucible cites.

In any event, doing that to your knife is certainly not recommended even if it isn't likely to signifigantly alter performance, it certainly wouldn't be covered under any reasonable warranty.
 
No harm done, I didn't mean to sound like I was implying that it was safe to take the knife to those sorts of temps, just that it was unlikely to seriously impact the performance unless you actually exceeded those temperatures.
 
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