Prep for first CPM 154 HT ( RC tested AGAIN)

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Taximanny

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I believe I'm ready tonight to do my first HT of CPM 154.

Plan is to wrap the blade in SS foil.
Is one wrap good?
I see some wrap up to 3 times.

Should I add tissue paper in the envelope?
Pros and cons of this ?

I'm making a slipjoint so I probably should wrap the spring separately ?

I'll pick up dry ice on the way home tonight from work.
If I don't make it to the ice this evening...
Might it still be usable the next evening, keeping it in a small cooler?

Thanks for any last minute suggestions.
 
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I only wrap once but I fold and press the edges twice. I don't put anything in mine, just press the air out before your last seem is sealed. The ice may keep but I would get it when you're ready to heat treat.

My process is preheat oven to 1400. Put in wrapped blades and equalize for 10-15. Ramp to 1950 and soak for 30-45. Plate quench and force air for 1-2 mins. After all blades are quenched, this is the time to straighten any warped blades. I made a little stand to keep my blades standing on the spine. Place blades in the pan, put in the crushed up dry ice, and pour in the denatured alcohol. I temper and ht in the same oven so I leave the blades in the dry ice until my oven cools off which is 2-3 hours. Temper twice for 2 hours. Good luck
 
I did a batch last night, and used the exact method and temps Matt gave. My only difference is I check and straighten during the second temper. I haven't had to straighten a blade in a long time because of the quench plates.
 
Just found out the dry ice in getting is pelletized.
So I'm thinking I won't have to add denatured alcohol.
I'll see when I pick it up.
 
You still need the alcohol. It will not transfer the heat from the blade to the DI without a liquid transfer media. The pellets are good, though. Saves smacking the DI bag with a wooden mallet. It sublimates a bit faster as pellets, but that isn't much of an issue.
 
Taximanny said:
I believe I'm ready tonight to do my first HT of CPM 154.

Plan is to wrap the blade in SS foil.
Is one wrap good?
I see some wrap up to 3 times.

Should I add tissue paper in the envelope?
Pros and cons of this ?

I'm making a slipjoint so I probably should wrap the spring separately ?

I'll pick up dry ice on the way home tonight from work.
If I don't make it to the ice this evening...
Might it still be usable the next evening, keeping it in a small cooler?

Thanks for any last minute suggestions.
Click to expand...

1. Probably what you are seeing is people referring to the number of times they fold the edges. I don't think I ever seen someone say they do multiple LAYERS of wrap.

2. won't hurt to add the paper, doesn't help much from what i've seen.

3 Is the spring from the same steel? If so the only difference will be your temper temps, so same package is fine as long as it will make good contact with your quench plates.

4 The Sub zero quench should be a continuation of your plate quench, You will get less benefit if done the next day. You want the dry ice slurry ready before the quench. Plate quench to room temp then start slowly submersing into slurry. Once it gets down to the -100 or so that your slurry is at your quench is done. Soaking doesn't hurt or help in the cold.
 
Ok so far so good....
Set program for 1400 for 15 min.
Than 1925 for 30 min.
Plate quenched than unwrapped to see if any warpage and it was good.
Let cool to room temp than put in slurry, of dry ice and alcohol for two hours.
Pulled out and still straight.
Getting ready to temper at 425 for two hours tonight and two more hours tomorrow in the morn.

I ground the blade cutting edge to .03 ( I'm noting everything)
I hope it won't be a bear to finish the grind😕
 
I wrap them three times - learned that from someone, can't remember who. It does seem to help reduce the discoloration of the blade. I don't add anything either as good tight wrap works just fine.

I however do a fast ramp up to 1950 and hold for 45. It takes my Evenheat quite some time to get there so I saw no need for a multi step ramp.

http://www.evenheat-kiln.com/?pg=technical-information&c=4&info=heat-treating-information&hti=9

My dry ice and alcohol temps showed -109 so it seemed to work and denatured alcohol is pretty easy to work with. Though I will say my LN tests have shown better results than dry ice in numbers and consistency. Its the consistency that sticks out in my mind the most. Normally I'll have variations of 1 to .5 RC across the blade. The LN makes the whole blade read the same. I wasn't expecting that as I don't recall reading that being an aspect of the LN bath.

The hardness levels I've experienced are the exact same as those in the link I sent. Makes for one serious long lasting edge and not brittle at all. I've tried chopping with my knives and have done the brass rod test without issue.

As far as the thickness goes on the edge, I get mine down to .020 or slightly less. Anything more is a pain to finish even with a 2x72. It's very hard steel when HT'd correctly. When I first got the edge down this far, I fully expected it to warp. I mean, that's just not much material considering the temps it'll see. So far not an issue and saves time later as noted.


I'm curious as to how yours turns out.

Justin
Black Raven Arms
https://www.facebook.com/Black-Raven-Arms-947029985371467/
 
Well here it is after subzero quench.
Looks like a little air got to it in the kiln.
Is this about normal or not?

Calling around today to see if I can get it tested somewhere here in St. Louis
Any builders in this area that might be able to help out?
 
You will see colours on your blade after heat treat. It's not a big deal. I agree that .03 is much too thick as well
 
After HT of the spring
Do I have to wrap in foil again for the spring tempering ?
Will be at 1100 for two hours
 
1100F will not need a wrap.

Take your edge to .015-.020" next time. On a blade that small, I would go to .010".

The colors mean pretty much nothing. I get peacock rainbows sometimes.
 
Ok found a lab to do the hardness testing here in St.Louis

Took it to them right after work.
BUMMER!
Came in at 55 to 56

They took three readings along the blade...
Should they of used the tang ? Nice and flat. Plus I sanded the tang smooth while at work today.
Can they get an off reading on a bevel?

Can I reheat treat the blade after it has been tempered?

Anyone got another recipe for CPM 154 3/32 blade?
A real downer !
 
What I understand with Rockwell testers is that they should be done on a flat surface like the tang or ricasso. Not the bevel.
 
It needs to be done on a flat surface as Shane stated. I hit them on the grinder so i have fresh steel showing.
 
Hardness testing can't be done on anything other than a flat, clean surface. Even a tiny bit of surface carbon will show lower results. This has gotten me a couple times. And it really can only be done on the flats. Angles or curves will also throw off the readings and show lower than expected results. I'd bet it's closer to 60+, especially with the lower tempering temps.

Clean off the entire ricasso, get it as flat as possible and then have them retest. I test right above the bevel where my makers mark goes so that the indentation will be hidden by the etch. Or leave it to show proof of hardness testing. Getting it removed entirely is really difficult as the indent is very deep relatively speaking.
 
Justice4all said:
Hardness testing can't be done on anything other than a flat, clean surface. Even a tiny bit of surface carbon will show lower results. This has gotten me a couple times. And it really can only be done on the flats. Angles or curves will also throw off the readings and show lower than expected results. I'd bet it's closer to 60+, especially with the lower tempering temps.

Clean off the entire ricasso, get it as flat as possible and then have them retest. I test right above the bevel where my makers mark goes so that the indentation will be hidden by the etch. Or leave it to show proof of hardness testing. Getting it removed entirely is really difficult as the indent is very deep relatively speaking.
Click to expand...

I'm doing just that now....
Even on the phone the guy said he must have a flat surface.
When he handed it to me back the marks were on the bevel.
I'm prepping it for another test.
And going to remind him to tell the guy testing it to use the flat tang.
He charged me $40 for the test.
If I remind him what he told me on the phone about a flat, he might just wave the retest.
If not I'm out another 40$.
At this point I don't care.
Just want another test in the tang.

Once I get my readings where I want them,, il stick with the recipe.
 
$40 to do it wrong? Plus the gas to their place. Nice. The next test should be free.

If things get to be too much of a pain and you can't find another maker locally, send it to me via USPS and I'll give it shot for free. I mean, it's so easy to perform *as long as things are clean and flat*.

I test on a test block first a few times and then the blade in multiple areas. My machine is from Grizzly, which is of course is a Chinese knockoff... However, it's been consistent and my cpm 154 blades seem to hold up and exhibit the ascribed properties of proper hardening/quenching/tempering.

Seriously, it takes all of two minutes to do.

his is a very simplistic description that is too the point.
http://www.gordonengland.co.uk/hardness/rockwell_superficial.htm



The thing I like about CPM 154 the most so far is that there is a window of hardness in which it will perform very well.



Oh, another thing I've noticed of the flat stock is that it has all been warped across it's length. I first noticed this when I started playing with the hardness tester.


Justin
Black Raven Arms
https://www.facebook.com/Black-Raven-Arms-947029985371467/
 
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