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View Full Version : CPM154? She failed the brass rod test.



JDW
03-02-2011, 07:01 PM
I made a test blade from CPM154, and my heat treat recipe is to pre heat to 1400, hold for 20 min. and heat to 1950, and hold for 50 min. then plate quench, with a fan blowing across the plates, when cool enough to handle, temper at 425 for 2 hours, air cool then repeat at 425 for 2 hrs. The blade is 1/8" thick at the spine, and full flat ground to .025 at the edge pre HT. I don't have a way to check RC, but with the brass rod test, she seems a little on the soft side, as the edge will roll slightly, and stay there instead of flexing back. According to the Crucible data sheet, with my time and temps, it should be 58-60RC. but they do show an oil quench. My question is, was my quench to slow, due to no contact on the bevel? And if it was, how can the problem be eliminated? I have no problems with 440C, A2, or D2 so I can't figure this out. In cutting dry hard oak the test blade holds up well, the edge didn't roll and she is still sharp, and I got prety rough with it shaving big thick pieces off of the oak, but the brass rod sure rolled the edge. Any thoughts will be appreciated.
Dale

James Terrio
03-02-2011, 08:00 PM
I'm not too sure about the brass rod test anymore. I'd put more faith in how she held up to that oak, which sounds just fine.

Romey
03-03-2011, 08:49 AM
My idea of brass rod test is cutting into brass. I,much like James dont have much faith in the roll test

JDW
03-03-2011, 05:06 PM
Thanks guys for your input. I don't put alot of stock in the brass rod test either, but I normally do not have an edge roll and stay in that position, so that kinda worried me at first, but so far the real cutting test looks good, I may drop down to 400 on the temper for the next one.
Thanks again
Dale

John Barker
03-08-2011, 10:51 AM
You don't need to hold it for 50 min. 25 min should be fine. I temper at 500F for 2hrs X 2. Stainless steels do not act like carbon steels.
-John

Cliff Fendley
03-16-2011, 11:44 AM
Ditto on Johns HT recipe for CPM 154. If it's a thick blade I'll hold for 30.

James Terrio
03-16-2011, 02:15 PM
I've been thinking about this since I use CPM-154 quite a bit and like it very much. Have you done any more testing? How's she holding up?

If anything, at least it didn't chip. I still think your results on oak sound pretty darn good. If it holds an edge well and isn't chippy, I'm a happy camper. I've had similar success with my CPM-154 knives, it's good stuff. (mine were HT'ed by Brad at Peters' so I don't know exactly the time/temp he used, but he Rc tested 'em and they all come out at 59.)

Thanks to John and Cliff for your input :)

JDW
03-18-2011, 08:13 PM
James, she is holding up real well, so far just cutting the oak, and my wife has used it in the kitchen some, and it makes a good steak knife, I think it is fine. I sure like the way the CPM154 takes a mirror finish. It may be going to Alaska or Texas on a hunt, on loan to a customer who is a guide, if he likes the design he will take it and give it a work out, I will know on Saturday if it gets to go, wish I could go too.
John, do you think the long soak would have any bad effect on the steel? I had read that it needed the long soak to get all the elements into solution.
Thanks Dale