Call for Charpy toughness samples

My wonderful wife Christina helped me setup this database to keep track of what has been done. I entered the current batch that is now boxed up and ready to send. I didn’t make it to the post today, but will tomorrow for sure. I’m going to enter the steels previously done, as well as those in the works so we don’t get multiple samples of the same steel. I’m sending the database to Larrin, so he can enter the charpy values and tested Rc#’s. I can add Rc#’s now again that I have my tester fixed. Once I get the database complete, I’ll ask Stacy to sticky it for reference for everyone. By summer, we should have most knife steels with “normal” heat treats tested, and we can start experimenting with pre-quenches, odd steels etc.

189AEB00-6C8C-496C-9440-66441F1FFBB2 by Wjkrywko, on Flickr

Remember, there have been three batches done before this one by me, plus whatever anyone else has sent in.

For reference, stage is 1: planned, 2: heat treated, 3: sent for grinding, and 4: charpy tested.

I’m going to have the database updated with all stages listed.
 
Keith Nix said:
I know I'm late to the party, but I'd love to help out if needed. I'm not yet set up for HT, but I do have access to mills and surface grinders.
I'd be happy to contribute in that way!
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Do you want me to send the next set of samples to you? It’ll probably be 6-8 weeks to get the next samples done. You can e-mail me at wjkrywko at gmail dot com.
 
Yes, Warren, and thank you for noticing. I want to participate in this in some way.

Email a'coming!

Keith
 
Is the length important. Thickness and width I can see being critical but wondering about length. What I mean is does it matter if it’s longer then the requested length.
 
JTknives said:
Is the length important. Thickness and width I can see being critical but wondering about length. What I mean is does it matter if it’s longer then the requested length.
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I’ll let Larrin confirm, but length is less important. I’ve done a few short samples for cross grain and Larrin said that was fine. The anvils are 40mm apart iirc.

Again, my apologies re being so far out of spec. I have my bandsaw fixed, and newer samples are much closer.
 
Warren, i noticed that the two Zapp PM steels are being tempered at what strikes me as a very low temperature. Do they respond that drastically to the lower temper?
 
jdm61 said:
Warren, i noticed that the two Zapp PM steels are being tempered at what strikes me as a very low temperature. Do they respond that drastically to the lower temper?
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I was going to do 400f, and I will do more samples with higher temper. I started low, and was going to walk up. Z-tuff wasn’t going to happen this round, but I did them due to the other thread. I didn’t walk it up as I got Rc60/61 with a 300f temper. Z-wear has the same protocol at 400f in previous testing. I’m hypothesizing using a lower aust temp, in this case 1975f, with a lower temper, might be tougher than the upcoming 2050f with 400f temper, due to keeping the grain size smaller.

Low temper isn’t well understood in high alloy steels. I have a lot of questions regarding optimum aust temp and temper temps. Much like 15n20, W2, 52100 responding well to lower aust temps, with relatively low tempers. The V4e shows the lowest retained austenite at 1875f, which is why I chose that temp for low tempers. More samples are coming, but upcoming samples will overlap with M4 and other upcoming steels, so I decided to send this batch out now.

Great observation.
 
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Yeah once I get caught up on the heat treating for a weekend (getting more and more busy) I plan on loading up the mag chuck and busting these out. I just had wondered about the length. Thanks
 
Length is not as critical but closer is better, of course.

Edit: the ASTM standard says plus or minus 1.0mm (on 55mm length).
 
I’m going to add 3v 1975f, 400f temper, and z-wear 1975f, 300f temper to the box. I did a blade for a customer last night, and it used the same program as these two steels needed. I’ll update the chart later today.
 
I just resent. If you don't get it soon, I'm

keithnix at bellsouth for net

You or anyone else on this forum may use that...
 
Any recommended heat treats for M4, or D2? I’ve got some M4 blades to do this weekend. I’m using standard heat treat for those. Also, anyone who uses Elmax want to chime in with recommendations?
 
Found something from my notes for M4, too, although it looks like a low (relative) temperature formula:

M4: 2100F (foil or coated), 30 min, oil/plate quench, CRYO, temper 400-500F 2 hours x3 (if no cryo, temper 1000F)

Somebody posted this one, but I don't remember where/who.
 
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