Is this hardened properly?

S

smorgan345

Joined
Mar 8, 2007
Messages
242
This is my first attempt at HT. It's a 440C blade, 3/32" thick. I just pulled it out of hardening and I plan to put it in cryo, but I just thought Id post pictures and see if this looks normal. My camera is the pits so sorry about the photos. The tip and edge appear to be tempered a bit? is that normal or did I screw this up? wrapped in ss foil, 1250F for 15 mins, 1600F for 15, then 1875F for 30 minutes and then plate quenched. Man those come out of the kiln hot! Thanks for any input.
 

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Yep it's OK,those are just oxide coloration from a little excess oxygen in the packet.Nothing to worry about.
Stan
 
SBuzek said:
Yep it's OK,those are just oxide coloration from a little excess oxygen in the packet.Nothing to worry about.
Stan
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Thanks Stan, you've been a huge help on this, it's been a ton of work but awesome. hope I get finished for Xmas. I'll post photos when I can. Thnx again.
Scott
 
As Stan mentioned dont worry about the color at all, What I do after heat treat is hit each one with a chainsaw file to ensure it skates a file.
I did recently have one from a batch that did not harden. Still need to figure out why.
CW
 
Looks to me like you wrapped it pretty well, that's a very clean blade. What little color you see will polish right off. You may see even more color after cryo but again, it's no biggie.
 
blindhogg said:
As Stan mentioned dont worry about the color at all, What I do after heat treat is hit each one with a chainsaw file to ensure it skates a file.
I did recently have one from a batch that did not harden. Still need to figure out why.
CW
Click to expand...

When you test it by seeing if the file skates, how hard do you push down? I'm asking because the steel originally had some scale on it and after I sanded it off and was trying to file the bevel, I felt like the file was wanting to skate at times when it got flat on the steel? Also, won't a file cut hardened steel? Thanks for your help.
Scott
 
A new sharp file will cut some hardened steel after temper,most files are 62-63 Rc,but the file should skate with moderate pressure right after quench and before temper.
At time you will have a thin oxide layer on the blade and the file will feel like it's cutting then after a couple of strokes it will start to skate.
Stan
 
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