Steel testing underway...

[aarongough]

This is pretty awesome!!! It just goes to show how the steel type is much less important than grind and heat treat. I'm not surprised to see A2 in the lead for a hard use knife. CPM 3v will start to show its advantages more as you push edge gemetry more extreme. I am surprised by the O1 results. I suspect more refined HT would move it up a few notches, especially since the shot in the dark HT worked out better than the kiln HT. I have been progressively been moving to the lower end of the HT range with my blades as I get better control of the equipment. They perform better the more I push toward the lower boundary.

I was surprised by the O1 results as well. I never would have guessed that the kiln treated O1 would do worse!

I think that the kiln treated O1 may have actually come out too hard. The long soak at high austentizing temperatures combined with the cryo treatment might mean that it would have to be tempered higher... With that said the edge on that blade failed in several tests by rolling?? We'll see when I take it in next week for hardness testing!

I was really hoping that this would put my mind at ease with regards to the steel I should be using. Silly me. It seems to have raised a few new questions!

 

[Willie71]

What take from this is to really look at the intended use of the knife, and the ideal geometry to inform the steel choice. Slicers will have significantly different optimum steels than hard use knives. The way they wear, and the loads on them will be significantly different requiring steels with differing attributes. Nailing heat treat is ultimately critical.

 

[aarongough]

What take from this is to really look at the intended use of the knife, and the ideal geometry to inform the steel choice. Slicers will have significantly different optimum steels than hard use knives. The way they wear, and the loads on them will be significantly different requiring steels with differing attributes. Nailing heat treat is ultimately critical.

Very true! I'm looking forward to getting the hardness test results to see if the heat-treat was ok on the test blades or not...

 

[Bomp]

Thanks for doing this test! I am sure it was a lot of work! I am actually not surprised that 01 did so well. I think it's underrated. I would say its only problem is that it rust so easy. Other than that it has always out-performed other steels for me. The strange part is the kiln treated 01 did worse than the forge version. Again thank you for the test.

 

[Huntsman Knife Co. LLC.]

Very cool to see these results! By carbide content alone 3V should have had the most edge retention. Im extremely surprised to see it was beaten. I still think 3V is just about the best steel out there for most blades and if you were to repeat this test with 100 blades I net it would come out on top. CPM 154 is pretty good as well.

Thanks so much for the time and effort you put into this testing! This was very fun to watch and a great learning experience. Keep up the great work!

 

[Nathan the Machinist]

The old standbys beating out the new super steels is not that uncommon. Quality A2 is an underrated steel, probably because there is no marketing for it. I'd have been curious to see how some quality D2 would have done in some of these tests concerning edge retention.

Thanks for posting your results.

 

[LRB]

With the kiln treated 01, you may have dissolved some of the carbides to solution by the long soak at 1500°. Also quenching in 150° oil would not benefit 01 either. 1475° at 15 to 20 minutes of soak should be plenty for 01, with a quench in oil at around 125° to 130°.
Just MHO, and I believe you mean well, but I see very little in your testing that could be called scientifically valid as far as determining which are the better steels.

 

[aarongough]

Thanks for doing this test! I am sure it was a lot of work! I am actually not surprised that 01 did so well. I think it's underrated. I would say its only problem is that it rust so easy. Other than that it has always out-performed other steels for me. The strange part is the kiln treated 01 did worse than the forge version. Again thank you for the test.

I agree that it was strange the way that O1 showed up in this test. I think the kiln version of O1 may have been too hard, and the backyard version may have been too soft.

I will confirm/disprove this soon by getting the blades hardness tested.

 

[aarongough]

With the kiln treated 01, you may have dissolved some of the carbides to solution by the long soak at 1500°. Also quenching in 150° oil would not benefit 01 either. 1475° at 15 to 20 minutes of soak should be plenty for 01, with a quench in oil at around 125° to 130°.
Just MHO, and I believe you mean well, but I see very little in your testing that could be called scientifically valid as far as determining which are the better steels.

The oil was not 150ºF, the steel was quenched in room-temperature oil until it was 150ºF. Room temperature at the time was 79ºF.

You're always going to dissolve some or all of the carbides in any steel at austenitizing temperatures. Given that the steel was in a spheroidized state before the heat-treatment (as almost all O1 is) if none of the carbides had been dissolved then there would be very little carbon in the steel overall...

I agree with you about the scientific validity of the tests. I've disclaimed multiple times that my results are only really valid in my shop, with my design of knife, with my sharpening setup. The whole reason I'm testing the steels in this setup is because other people's results may not hold in my situation, same as my results may not hold up in their situation.

 

[aarongough]

The old standbys beating out the new super steels is not that uncommon. Quality A2 is an underrated steel, probably because there is no marketing for it. I'd have been curious to see how some quality D2 would have done in some of these tests concerning edge retention.

Thanks for posting your results.

Interesting point about there not being any marketing for the standard tool steels! I'll probably be doing more tests in the future... I have to nail the heat-treat for A2 by the looks of it, so that wil entail more testing even just for that.

 

[aarongough]

Very cool to see these results! By carbide content alone 3V should have had the most edge retention. Im extremely surprised to see it was beaten. I still think 3V is just about the best steel out there for most blades and if you were to repeat this test with 100 blades I net it would come out on top. CPM 154 is pretty good as well.

Thanks so much for the time and effort you put into this testing! This was very fun to watch and a great learning experience. Keep up the great work!

Thanks mate!

I'm also very surprised that CPM3V and CPM154 didn't top out the results. I have yet to confirm the validity of the tests by getting the hardness of the blades checked...

If I have to go with a non-stainless steel then I want to look into getting Titanium Carbon Nitride (TiCN) coatings done on my blades to prevent corrosion. Not sure if it's worth it yet, but if it is then CPM3V may end up being what I use because it's higher tempering temperatures allow more latitude in process after heat-treat...

 

[Varga Knives]

Thanks for all the hard work you went through on your testing. LIke everyone else I'm surprised at the results for the CPM154 and I look forward to the rockwell results. Really do hope to see more tests in the future.

 

[Don Nguyen]

Aaron I'm surprised too at the results. Very cool. I've actually been eyeing A2 for a while, just because it'll make the quench/grinding steps easier on my heart

 

[Willie71]

I think your O1 was heated too high in the kiln. Since there was no grain refinement prior to heat treat, we have no idea of the grain size going into the test. Heating a bit lower helps prevent the hypereuctoid steals from carbon precipitation to where you don't want it, such as in the grain boundaries. The edge rolling suggests it is on the soft side, or the geometry is too thin, but the specs you gave don't support that. I suspect the forge O1 had inconsistent heat resulting in the weird bending, but the belly appears to have been spot on by the fine slicing test. O1 is known for its keen edge.

 

[aarongough]

Thanks for all the hard work you went through on your testing. LIke everyone else I'm surprised at the results for the CPM154 and I look forward to the rockwell results. Really do hope to see more tests in the future.

Thanks mate!

I might be getting the rockwell and decarb tests as early as this afternoon... If it's not this afternoon though it will have to be late next week unfortunately.

 

[Willie71]

I think it would be very interesting to see the results if all of the steels had appropriate grain refinement prior to HT.

Thank you for doing all of this testing. Great food for thought.

 

[aarongough]

Aaron I'm surprised too at the results. Very cool. I've actually been eyeing A2 for a while, just because it'll make the quench/grinding steps easier on my heart

Hey Don! Yes it was a very nice change to use some air-hardening steels I quite enjoyed the process!

 

[aarongough]

I think your O1 was heated too high in the kiln. Since there was no grain refinement prior to heat treat, we have no idea of the grain size going into the test. Heating a bit lower helps prevent the hypereuctoid steals from carbon precipitation to where you don't want it, such as in the grain boundaries. The edge rolling suggests it is on the soft side, or the geometry is too thin, but the specs you gave don't support that. I suspect the forge O1 had inconsistent heat resulting in the weird bending, but the belly appears to have been spot on by the fine slicing test. O1 is known for its keen edge.

That's certainly very possible! There are so many variables in all this stuff, it's no wonder that the same steel from two different makers can be so different!

The forge heat-treat O1 was definitely screwed up in some fashion. I'm hoping the hardness testing will shed a bit of light on that. The place I'm going said they can give me an idea of whether or not the blades were decarbed or not too which is always potentially a factor. I may cough up the cash to get metallographs done, but we'll see whether they think it's necessary and how much it's going to cost.

 

[Don Hanson III]

I'm not too surprised with your results, as I've had simple carbon steels out perform the 'super' steels. W2 beats everything I've tried, but not all W2 is the same...

I've also had 'forge' heat treated blades out perform 'kiln' heat treated blades more than once, also had the opposite. In theory the kiln treated 01 blade should beat the forge treated one, but nothing is written in stone. Results will usually be more consistent with a kiln, but not always better. It takes practice to hit the right stuff with a forge.

Pick the steel you like best and run the same test with 3-4 blades of same, but tweak HT for each blade. Could be interesting.

 

[aarongough]

I'm not too surprised with your results, as I've had simple carbon steels out perform the 'super' steels. W2 beats everything I've tried, but not all W2 is the same...

I've also had 'forge' heat treated blades out perform 'kiln' heat treated blades more than once, also had the opposite. In theory the kiln treated 01 blade should beat the forge treated one, but nothing is written in stone. Results will usually be more consistent with a kiln, but not always better. It takes practice to hit the right stuff with a forge.

Pick the steel you like best and run the same test with 3-4 blades of same, but tweak HT for each blade. Could be interesting.

That's the plan for next week I think... I'll be going to the testing place to get the blades tested next Friday, so I'll try to do up a couple more A2 blades before then, use different heat-treats and get them tested while I'm there are well.