help with 440c and cm154

[funkyjedi]

I just heat treated a 440c and then a cm154 blade. Reset the furnace in between, etc.

Here is the 440c. You can see the color change along the blade. I took it to 1400 for 10 min. Ramped up to 1900 for 30 minutes, then quenched between .75" aluminum plates and hit it with my compressor till holding temp. I went ahead and put it in a preheated 375 tempering oven. I am not sure if it looks like it heated completely through based on the color. I've only ever done one other 440c with my PID controlled furnace, but it seems like it was the dark gray color the entire blade...Also I included a pic of the envelope, as maybe that will tell you something I don't know.



Then on to the 154 cm... I did same exact procedure as before, except I went to 1950 and held for 30 min. It had a similar color line. weird. I'm waiting to put it in a 400f oven when one becomes available. I took a file to it and it doesn't make the glassy skate sound, but it doesn't really bite in either. I don't have a rc testing device, so I'm going on the recipes I've found online (usually from this site..)





Any ideas you guys have would be appreciated. Maybe they are fine, but the color line on the edges threw me. The smaller 154 has not been ground, while the larger 440c has a 10" wheel hollow grind...

Im scratching my head.

Thanks for reading.

 

[Wayne Bensinger]

Hi Hunt,
I've looked pretty close at all your pics and they look pretty normal from what I can see, although I'm no expert on heat treating I do use both of those steels often and I can say that my blades always look similar and so do my envelopes, they kind of get a bit flaky/crispy around the edges. The thin edge of the blades usually turns purple/blue and they have the same foggy blue/purple/straws colors as your blades do there. Unless I'm doing something wrong also. Maybe Mr. Cashen can confirm.

Wayne

 

[funkyjedi]

Thanks for the quick reply, Wayne. I appreciate it.
I feel better knowing someone else gets similar results as far as color go. I've been using 1095 and w2 for a while and they are far easier to heat treat. But, you know if you have a digital kiln, you gotta use it

I am tempering both now. Ill get a chance to put an edge on them in the next day or so and see how they fare.

I really do appreciate the help.

chris

Hi Hunt,
I've looked pretty close at all your pics and they look pretty normal from what I can see, although I'm no expert on heat treating I do use both of those steels often and I can say that my blades always look similar and so do my envelopes, they kind of get a bit flaky/crispy around the edges. The thin edge of the blades usually turns purple/blue and they have the same foggy blue/purple/straws colors as your blades do there. Unless I'm doing something wrong also. Maybe Mr. Cashen can confirm.

Wayne

 

[Self Made Knives]

I get that a little sometimes too, I'm guessing the majority of the discoloration is on the seam side of your pouch. Probably just not air tight enough. I put my cutting edge towards the fold in the middle and the spine on seam side, just in case. I've also noticed that you can get a weird array of color if you wipe the blade with acetone right before putting it in the envelope too. It leaves some kind of residue behind I guess, but you'll get almost a rainbow sometimes.

 

[bladegrinder]

I used 440-C for years and do my own heat treating, and testing with a Rockwell tester. what you have there looks normal.
I mostly use CPM-154 now and pre-grind all my blades pre ht treat, going to 1400 for 15 min. then ramping to 1950 for 30 min.
they come out between 61-62 RC. when I started going to those higher temps I noticed the foil wanting to weld or stick to the blade,
now I dust them with baby powder "talc" NOT the cornstarch kind...and that solved the problem. I also noticed CPM-154 comes out with much less heat color on the blade so I don't thing those rainbow colors have much to do with the heat treat final out come.

 

[funkyjedi]

You guys are awesome. Thanks for the help. I took them through the tempering cycles, and as far as I can tell they should be good. It was just an odd thing seeing the color on the one side of BOTH blades.

I really do appreciate the help! The little one looks like this right now... I dont know why I thought I'd do a dagger.. they kick my butt everytime.
..

thanks again!!!

-chris