Let's All Laugh At The New Guy And His "rainbow" Heat Treat

So being a guy who has made a bunch of different things I approached this knifemaking thing with, perhaps, a dash too much confidence. Surely, I thought, my knives will be beautiful and functional and great from the get go. I always seem to forget how humbling it is to learn a new skill.

So have a look and a chuckle at my unicorn poop colored blades. I can't decide whether to scrap em, normalize and re-quench or just slap some wood on em and see how they fare.





For those who are interested its O1 that I brought up to critical heat in a charcoal forge. Being afraid to burn em they only soaked at temp for a couple minutes (not long enough I'm sure). Other than some obvious decarb they looked OK after the quench in canola. After 2hrs at 450 there was a bit of blue on the bevel of the smaller knife and a nice straw on the bigger one. After the second 2hr cycle they came out like you see em.

Next time I'll use a black pipe muffle to try to minimize the scale.

I'll also have to grab some 1084 to play with until I can source all the parts for the propane forge I'm building (what I'd do for a Home Depot less than 4 hrs away).

Anyway, I would be grateful if any of you had any tips or ideas for how to proceed.

Cheers!

 

Never got colours like that when I did 01, actually looks nice. Mind you I temper at 400 so not hot enough for pretty colours.

 

I'm thinking I'll have to start my next temper around 400 too. Funny thing - my fears about the blue indicating that the steel will be too soft might be unfounded. The thing is still so hard my files won't bite it at all. I'm getting nowhere trying to file the bevel to final shape.

 

Still near Rhc 60, check bottom of page for 01
http://www.cashenblades.com/heattreatment.html

 

Steel needs to be very clean and smooth, any contamination or very rough surfaces can create false color indications

 

Hmm, great info on this page. Thanks for the link, John!

 

A few years back I had some CPM154 that went all rainbow on me. Unfortunately, it's surface only oxidization and rubbed off pretty easily.

 

It'll buff out

 

Surface oxidation can be deceptive. Try some cutting tests to see how it holds up.

 

I think they look awesome

 

Bit that I have done many... I temper at 400 in a bbq and all of my knives look similar after tempering. I would say my unicorns are a little more evenly coloured is all. I didn’t know any better or ask anyone. I slapped handles on them and sharpened them up so far so good??

 

Looks like case hardening I've seen on firearms. Probably the charcoal you used imparted carbon into the steel.