oops cpm154 annealing

69*camaro

Well-Known Member
I could use some advice after an obviously poor decision. Bought some CPM 154 from Boss. Cut into big rectangles with a bandsaw. Profiled on the bench grinder. I felt like I may have overheated it in the profiling, so I decided to anneal it. Did not think about needing to use the SS foil. OOH man, bad surface oxidation, warped beyond my wildest expectations. So I straighten and take the (8) blades to the platen to try to fix them. Burned up several 50 grit blaze belts and am not happy!!! How do I get this oxidation off without spending more in belts than the steel is worth?
 
Another question, how did you try to anneal it? Pickling in white vinegar should take off the fire scale but we sort of need to know if you took the steel above critical and how it was treated afterward.

Doug
 
What temp and how long was your anneal?

when profiling a blade by grinding it like you have seen in a dozen videos, dunk it occasionally and ignore the purple coloring you see around the edge. You don't need to correct for that. Profiling by grinding doesn't get you anywhere near critical temp so you don't need to worry about wrecking the steel or having issues with localized hardening. When you get it profiled, just go about your business finishing the rest of the blade.
 
I took the temp to 1650, hold for 2 hours, drop at 25 degrees per hour to 600, then let cool in the furnace. Thanks Boss, I won't make this mistake again.
 
Last edited:
From that temp recipe you may have made Pearlite...a non-martinsitic form of "hardened" steel.

Mistakes just happen. It's part of the process. I have the most beautiful set of $75 mammoth ivory scales glued to the front of my drill press as a reminder. I drilled one hole wrong on one scale that ruined the set beyond any salvage.
Another time I programmed a knife to anneal, completely messed up the programming, then forgot I had it in the oven. 3 hours at 2150F reduces a knife to layers of crispy, charred flakes of metal.

welcome to knife making!
 
Ok, you did actually anneal it but you might have also increases the size of the the carbides which might give you some problems when it comes to drilling and grinding. You might try a sub-critical anneal, spherodizing, if this seems to be a problem.

Doug
 
You might be able to recover from this one. However, there's not one of us who doesn't have a growing pile of "learning experiences". What I can't understand is if we learn more from our mistakes than we do from our successes why aren't I a flipp'n genius by now.

Doug :s12138:
 
Back
Top