Call for Charpy toughness samples

[mete]

Cold Steel used to make a very fine hunting knife of A8 [not mod ] Then knife in every respect was excellent . But after a while there were complaints about the steel . Seems that they changed to some poor Chinese steel but still called it A8 ! I'm keeping mine !

 

[hugofeynman]

Cold Steel used to make a very fine hunting knife of A8 [not mod ] Then knife in every respect was excellent . But after a while there were complaints about the steel . Seems that they changed to some poor Chinese steel but still called it A8 ! I'm keeping mine !

Not AUS8, Mete? Not meant to be a smart ass!!!

 

[Natlek]

We tested the three 15N20 samples and got somewhat disappointing results. We got values of 8.9, 9.0, and 23.8 ft-lbs. So we got two low values and one much higher value, meaning it is difficult to conclude much from the tests. None of those values are anywhere close to the toughness measured for AEB-L. The results might be inconsistent due to their prior use as saw blades, but we're not really sure.

The heat treatment was: subcritical anneal at 1175°F, austenitize at 1475°F, quench in Parks #50, liquid nitrogen for 20 minutes, temper 2x at 375°F for final hardness of 60 Rc.

There's a lot of waste 15N20 steel here and I have never find / fabricated product from this steel / with more then 44-48 HRC hardness . They must have reasons for that ?

 

[Larrin]

There's a lot of waste 15N20 steel here and I have never find / fabricated product from this steel / with more then 44-48 HRC hardness . They must have reasons for that ?

For the application it is intended that is the chosen hardness.

 

[Larrin]

Yes, in a professional journal as examples of what can be done in “real world conditions” rather than with ideal equipment. It might be interesting to float this idea.

Warren

There are plenty of journal articles out there where they heat treated in small furnaces. The main thing preventing publication in a journal would be the lack of micrographs.

 

[mete]

Hugo, sorry but that's how tight the memory about a company's screw up is ! Such a fine knife and they ruined it ! Besides at my advanced age a million different steel grades does get confusing !!

 

[hugofeynman]

Hugo, sorry but that's how tight the memory about a company's screw up is ! Such a fine knife and they ruined it ! Besides at my advanced age a million different steel grades does get confusing !!

No problem, Mete!

Hopefully I can get an A8mod sample so Larrin can test it. And Ultrafort (Maraging steel). I have a big chopper made of it (3/8” thick) but don’t have much time for tests. Just did some chopping in a 2” dead and super dry olive branch that was really hard and the edge was intact. The damn branch was so dry that I needed more than 10 swings to cut it in half!

I’m no knifemaker, so I depend on my makers/friends to make those small steel pieces.

 

[mete]

Maraging steel , you don't here much about that theses days. That was my thesis progect back in the early days of maraging. They do make fencing swords of that now.
Unfortunately in those days few had cameras so I have no photos of me making it .Induction furnace, forging hammer etc, the whole show !

 

[Willie71]

I’ve got the rest of the day set aside for heat treating today.

I’ll see how far I get.


Edit: six z-wear conditions in the oven as we speak.
Warren

 

[kuraki]

I've got my kanthal and everything for repairing my furnace now so hopefully I can move along soon with samples.

 

[Darrin Sanders]

I haven't checked this thread lately but it seems to be gaining interest. Larrin, if you have any particular alloy, H/T protocol, or any combination thereof in mind, let me know and I'll make and H/T some coupons and get them to you. I'm a packrat so I have lots of coupon sized pieces of steel (all properly marked) laying on my steel shelf. If you want anything tested that I don't have, I'll get some from Chuck. Thanks to everyone who is participating.

 

[Willie71]

I haven't checked this thread lately but it seems to be gaining interest. Larrin, if you have any particular alloy, H/T protocol, or any combination thereof in mind, let me know and I'll make and H/T some coupons and get them to you. I'm a packrat so I have lots of coupon sized pieces of steel (all properly marked) laying on my steel shelf. If you want anything tested that I don't have, I'll get some from Chuck. Thanks to everyone who is participating.

Check the pic I posted last page to make sure we aren’t duplicating samples. Chuck was quite generous for this project.

Warren

 

[Larrin]

I haven't checked this thread lately but it seems to be gaining interest. Larrin, if you have any particular alloy, H/T protocol, or any combination thereof in mind, let me know and I'll make and H/T some coupons and get them to you. I'm a packrat so I have lots of coupon sized pieces of steel (all properly marked) laying on my steel shelf. If you want anything tested that I don't have, I'll get some from Chuck. Thanks to everyone who is participating.

3V, 4V, CPM-M4, Vanadis 4 Extra are all missing I believe. Another possibility is to pick one standard steel like AEB-L and to try more heat treatments like different types of prequenches, for example.

 

[Willie71]

3V, 4V, CPM-M4, Vanadis 4 Extra are all missing I believe. Another possibility is to pick one standard steel like AEB-L and to try more heat treatments like different types of prequenches, for example.

I’ve got 7 conditions in z-wear/cru-wear coming, and two conditions in 8670 and W2 coming. I should be able to send the x-wear by the end of the week, and maybe one or two others depending on how my real job plays out this week.

 

[rodriguez7]

3V, 4V, CPM-M4, Vanadis 4 Extra are all missing I believe. Another possibility is to pick one standard steel like AEB-L and to try more heat treatments like different types of prequenches, for example.

Was Nathan making up some pieces in 3v after all? I would imagine he could do 4v with his enhanced heat treat too! But I’m sure he’s a busy guy.

 

[Larrin]

Was Nathan making up some pieces in 3v after all? I would imagine he could do 4v with his enhanced heat treat too! But I’m sure he’s a busy guy.

He said he will see if he can contribute but has not committed to anything.

 

[kuraki]

I have M4 and 4V on hand for this.

 

[Larrin]

I have M4 and 4V on hand for this.

Oops! I see that in the thread now.

 

[Larrin]

Here is an example of a set of heat treatments that could be performed with AEB-L:

 

[Willie71]

Here is an example of a set of heat treatments that could be performed with AEB-L:

Is this something that can be advantageous in steels like z-wear or 4V? Is it worth experimenting with?