Toughness of 52100?

[rcb2000]

Hi All,
Been on the forums for a while,, and finally decided to stop spending money buying knives,, and start making(who am I kidding, I'll still buy).
This was my first attempt.. D2 treated by Peters.

to this

to this

I really love the process,, but today I decided to put through its paces. Its convex edge held perfect beating through a 2x4,, jabbed it hard, and pryed into the same 2x4 with virtually no loss in edge.
However,, part curiosity, part frustration (being snowed in for 3 days),, I hammered it through a nail.. no problem,, through another nail... CRAP!! Yes a tiny chip,, which I guess is completely to be expected.

Which leads me to my question: My next project will be a large (10" blade, 15" overall) chopper,, made of 52100. Seeing as Swamprat and SYKCO use this with their own heat treat,, is this a good steel for this purpose?

I really appreciate any advice.. thanks!

 

[BluntCut MetalWorks]

Here is a link to my test of 52100 & D2 small blades at 62+rc. Oh in this thread, please ignore the 2 words - could cause eyes strain to other makers due to excessive rolling - "Super Quenched".

http://www.bladeforums.com/forums/s...est-amp-arms-exercise?p=14420660#post14420660

It's easy to make a blade tough by keep it thick. I test impact toughness near breaking geometry threshold for my heat treated 52100 & D2 blades. Ultimately, I will make more choppers mostly in 52100 and a few CruV & 1 or 2 D2.

 

[rcb2000]

Here is a link to my test of 52100 & D2 small blades at 62+rc. Oh in this thread, please ignore the 2 words - could cause eyes strain to other makers due to excessive rolling - "Super Quenched".

http://www.bladeforums.com/forums/s...est-amp-arms-exercise?p=14420660#post14420660

It's easy to make a blade tough by keep it thick. I test impact toughness near breaking geometry threshold for my heat treated 52100 & D2 blades. Ultimately, I will make more choppers mostly in 52100 and a few CruV & 1 or 2 D2.

Lots of great info, thanks!
Do you think if I ask Peters to shoot for 58,, I would get a blade more likely to roll, rather than chip during chopping?

 

[jdm61]

A year or two ago, I asked Kevin Cashen what steel or steels he would recommend for a reasonably priced line of "mid tech" outdoor knives using readily available and reasonably priced carbon/tool steel? He recommened using O1 for knives with blade under say 5-6 inches, which was no surprise. He loves the stuff and the extra alloying elements not only make for a nice slicer but also give some extra abrasion resistance over plain carbon steels. What he recommended for "tougher" big blades did surprise me a bit. He said that 52100 HT'ed using the lower 1475F temp that he had been working with was just the ticket. Your mileage may vary, but this iis coming from a guy who makes a lot of L6 knives, so he knows what tough is when it comes to regular cast tool steel. But in the case of the Champaloy variants of L6 that he prefers, most of us probably don't want to mess with it so the 52100 apparently works well without driving you nuts trying to machine and drill it.

 

[me2]

I personally would not choose 52100 for a chopper steel like a 10" blade. A 10" kitchen knife is another story, but not a chopper. Of course, I wouldn't choose 1095 for a chopper either, but ESEE and Ontario do so and have for years. If heat treated properly, your 52100 will be good for that purpose. I just prefer steels with less carbon for choppers, 5160, S7, 1055, 1075, etc.

 

[rcb2000]

I personally would not choose 52100 for a chopper steel like a 10" blade. A 10" kitchen knife is another story, but not a chopper. Of course, I wouldn't choose 1095 for a chopper either, but ESEE and Ontario do so and have for years. If heat treated properly, your 52100 will be good for that purpose. I just prefer steels with less carbon for choppers, 5160, S7, 1055, 1075, etc.

Very true,, I read somewhere a good heat treat on mediocre steel is better than a mediocre treat on good steel...

I'm super new to all of this,, but if I tell Peters what characteristics Im looking for,, would they be able to work towards that?

 

[BluntCut MetalWorks]

Design your blade best for intended use first. Chopping what & usage style are also important. When new at something, choose safe & easy ht but excellent steel such as 80crv2. My 80crv2 chopper at 59rc with very thin edge geometry is tougher than my 52100 58.5rc. Move up to steels with higher carbon when you or someone custom ht at a higher(spell time consuming = expensive) level. Peters probably will just normalize, then harden 52100. While optimal ht involve multi thermal cycle to refine grain. For a chopper you want high impact toughness and high edge stability to resist deformation from lateral forces. Edge retention (higher carbon steels) is a bonus because only relevant if only if your edge stay intact in the first place.

bottom line - go with 80crv2. Happy ending.

Lots of great info, thanks!
Do you think if I ask Peters to shoot for 58,, I would get a blade more likely to roll, rather than chip during chopping?

 

[jdm61]

I personally would not choose 52100 for a chopper steel like a 10" blade. A 10" kitchen knife is another story, but not a chopper. Of course, I wouldn't choose 1095 for a chopper either, but ESEE and Ontario do so and have for years. If heat treated properly, your 52100 will be good for that purpose. I just prefer steels with less carbon for choppers, 5160, S7, 1055, 1075, etc.

ESEE and Ontario tend to leave there 1095 rather soft. 1095 at 55Rc is going to be pretty tough. The thing about the 52100 at the lower austenizing temperature is that only about .85% of the carbon actually goes into solution. Slightly different. Like another post said, the 80CrV2 is good and some say better than 5160 because it is tough, but holds an edge better. I think like with many steels, it is the OTHER alloying elements that are responsible for those improvements as much as having a bit more carbon. The 80CrV2 has slightly less chrome as 5160, The same silicon as the upper limit for 5160, but 25% more carbon and perhaps more importantly, small amount of vanadium, about the same as W2. That says that is kind of resembles a slightly lower carbon 1086M, but with maybe a little more chrome. Similar to the stuff that Howard Clark uses for his non L6 katanas.

 

[jdm61]

Design your blade best for intended use first. Chopping what & usage style are also important. When new at something, choose safe & easy ht but excellent steel such as 80crv2. My 80crv2 chopper at 59rc with very thin edge geometry is tougher than my 52100 58.5rc. Move up to steels with higher carbon when you or someone custom ht at a higher(spell time consuming = expensive) level. Peters probably will just normalize, then harden 52100. While optimal ht involve multi thermal cycle to refine grain. For a chopper you want high impact toughness and high edge stability to resist deformation from lateral forces. Edge retention (higher carbon steels) is a bonus because only relevant if only if your edge stay intact in the first place.

bottom line - go with 80crv2. Happy ending.

For the 52100 that we can get, I would think that you would need to "normalize" first at a fairly high temp like 1650F to bust up all of those little spheroid carbides and then do a couple of more cycles at normal defending temperatures to reduce the grain you grew doing the first cycle.

 

[BluntCut MetalWorks]

Yes, you're right. Normalize (~1650F 15minutes soak) is the first step in my ht. I also do 5 minutes soak for each thermal too (a slight re-diffusion to re-arrange thing - haha), descending temp cool with air, plate, oil(s) w/o clay coated blade... std 52100 grain refinement peak around 3 cycles. anneal for fine spheroidize carbide before hardening yielded inclusive result for me, hence I drop this step after a bunch of tries. Then add some more steps, eventually lead to my hardening taboo quench My next SQ 52100 chopper probably will aust harden below 1440F, temper for 62rc working blade.

For the 52100 that we can get, I would think that you would need to "normalize" first at a fairly high temp like 1650F to bust up all of those little spheroid carbides and then do a couple of more cycles at normal defending temperatures to reduce the grain you grew doing the first cycle.

 

[rcb2000]

You guys are great, thank you so much for your help!