Carbide?

[Gevir Knives]

So I heat treat with a charcoal forge at home. Powered by a hair dryer. I realize not idea bit it's what I have.
I quench in canola oil and I get this happen a lot. The material is recycled saw mill blades .
Is this carbide binding? I have been told it's the carbon splitting frim the other metal.
So what to do ? Do another heat reat with more even heat ie. Move the knife around to not have got spots? And if is my quench need more time?
There gone trough two tempering cycles. Maybe this batch try to cm sand down the pattern . I feel there's some integrety/ strength issues

 

[S.Alexander]

It's called decarburization (decarb). It happens when you forge and heat treat your blades. You can grind or sand past it to get to clean steel below.

 

[mete]

That's exactly what happens , even in Canada !
Some wrap in SS foil or paint with solution that prevents decarb. For the foil the steel must be at least an oil hardening type or air hardening.

 

[Gevir Knives]

Right . Deacarb. That's it.
Been awhile since I did it this way. Had access to an oven for a bit and it didn't happen . Forgot this happened the even that process was a lot different
Thanks guys. It looks neat but too uneven and messy to keep . Hand sanding tonight

 

[Rick Marchand]

Dude... Come visit... We talk... We fix.