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Video
Here is a video version of the following information:
Development
In March 2024 Joey Berry of Pop’s Knife Supply called me and said he wanted to develop a new steel. He said that their most popular steel was 80CrV2 and so he wanted to make “80CrV3.” “You mean 80CrV2 but with a little more vanadium?” He said no but some kind of “sequel” to 80CrV2 that would be more exciting. I told him that doesn’t give me much to go off of but I would think about whether I had any good ideas along those lines. I thought about gaps in the market in the area of low alloy knife steels (“Carbon steel”) that would also be usable by the knifemaker that is buying 80CrV2. It occurred to me that our selection of high nickel steels is very limited; 15N20, L6, and 8670 are pretty much it. These steels are high in toughness and offer good hardness to go with it, but have no real wear resistance to speak of. 80CrV2 is in a similar position just without the nickel. I thought if we added some tungsten and vanadium to a high nickel steel we could make the steel more balanced; give it some wear resistance along with the high toughness. Those carbide pinning elements would mean that the steels are more beginner friendly for forge heat treating. 15N20, for example, already sees grain growth around 1500°F (815°C) and so its toughness drops very rapidly even when only slightly overheated. If the tungsten and vanadium were kept in check the forgeability, grindability, and polishability would remain high. This would also offer an alternative to other tungsten/vanadium steels like Blue #1, V-Toku2, Wolfram Special, 1.2519, and others. Those steels don’t have much toughness to speak of, so we could combine the best of the nickel steels with the best of the tungsten/vanadium steels. Another exciting element with the high nickel is the possibility to use the steel in pattern-welded Damascus as a “bright” layer. This gives an option for a higher wear resistance steel with better edge retention for that component of the Damascus. I told Joey about my idea and we decided to move forward with it.
We took the composition I came up with to a steel mill in Europe and they agreed to make it. I spent a bunch of time working on optimal annealing for the somewhat similar 15N20 based on the limitations of their production annealing process. Based on that we generated an annealing procedure to make the steel respond well to forge heat treating.
Composition and Tungsten/Vanadium Carbides
Here is the composition of Pop’s ProCut compared with other grades in its category. The far right column says “MC (%)” which is a calculation of how much total vanadium and tungsten carbide each steel contains after heat treating. One thing you will notice is that since tungsten is a heavy element it does not contribute as much to the MC as you might expect. For example, CruForgeV with 0.75% vanadium has more MC than Wolfram Special which has ~2.25% tungsten. ProCut uses a combination of vanadium and tungsten in a similar fashion to O7 and 1.2519 steels. So it has similar MC to steels like Blue #1, 1.2519/O7, and Wolfram Special, and more MC than Blue #2 and O1. The other nickel nickel steels (15N20, L6, and 8670) of course do not have any MC. These very hard carbides give the steel wear resistance.
Austenitizing, Tempering, and Hardness
A major goal for this grade was to be “easy” to heat treat with a forge. This requires a wide range of austenitizing temperature where full hardness is achieved while avoiding a toughness drop with higher temperatures. 80CrV2 steel varies a lot with starting microstructure, and two of the mills that make the steel lead to very different heat treating response:
So we wanted to avoid this issue that 80CrV2 sees. We did this by keeping the chromium low and also working with the manufacturer to dial in the annealing procedure so that carbides aren’t too coarse (making them difficult to dissolve). I also compared the austenitizing response with my recommended anneal (described later):
You can see that the hardness reaches its maximum around 1475°F and then does not change above that temperature. If using the anneal I recommend the microstructure is a bit finer and so this can be dropped even further to 1375°F. Thus for heat treating in a forge you can heat the steel to “a shade brighter” after reaching nonmagnetic and the steel will fully harden. If you forge and follow the recommending normalizing and annealing procedure you can even quench from nonmagnetic if you wish.
If the steel is austenitized in that range (1475°F or higher) the tempering is roughly the same regardless of the austenitizing temperature. Here are datapoints for both 1550°F and 1625°F:
You can see that the hardness is relatively high, still 64 Rc after tempering at 300°F, which is generally as low as I recommend for tempering most any steel. With a 450°F temper the steel is still above 60 Rc.
Toughness
Austenitizing
In our heat treating and toughness experiments we found three different regions of toughness behavior:
Below 1500°F, the steel shows an increase in toughness with increasing temperature. From 1500-1575°F the toughness is roughly flat. 1625°F and above shows a big jump in toughness where it is flat again up to at least 1675°F. The reason for this behavior we figured out by looking at the microstructure. These images were taken by knifemaker Shawn Houston of Triple B Knives:
1425°F, 400°F temper
1475°F, 400°F temper
1600°F, 400°F temper
You can see that the carbide content is significantly reduced by austenitizing at 1475°F as opposed to 1425°F. This significant change in cementite (iron carbide) raised toughness. Then when the temperature is further increased to 1600°F and above, virtually all of the cementite is gone and all that remains is the small volume of hard vanadium and tungsten carbides. The presence of these small carbides is what prevents grain growth even at high temperatures. The carbides “pin” the grain boundaries.
15N20 and L6, in contrast, show a drop in toughness at much lower temperatures because they do not have those carbides to pin grains. The steel 1.2519 does have the W/V carbides but it sees a drop in toughness above 1500°F because it gets excess carbon in solution, leading to plate martensite. The carbon content in ProCut is controlled so that the matrix carbon does not reach excessive levels even at high temperature. This gives ProCut a very wide austenitizing range.
Tempering and Toughness
Like many other knife steels, ProCut sees a peak in toughness with a tempering temperature of around 450°F (230°C). Above that the toughness drops due to a phenomena called “tempered martensite embrittlement” which happens in all steels. There is lower toughness with tempering at lower temperatures as well, of course, corresponding with the higher hardness. The behavior of toughness with tempering temperature is roughly similar whether using the higher or lower austenitizing temperature range.
Hardness vs Toughness
This creates two different heat treating ranges, where the steel can be austenitized high (1625-1675°F) to max out toughness with some cost to wear resistance and edge retention, or austenitizing lower (1475-1575°F) to retain more carbide for wear resistance. The steel still maintains a toughness advantage vs previous tungsten/vanadium steels due to the nickel addition and controlled carbon content with the lower austenitizing range. However, with the high austenitizing range it achieves levels of toughness similar to 8670, 15N20, and L6 but with enhanced wear resistance due to the small tungsten and vanadium carbides.
To compare with other steels you can look at the following chart:
Grinding and Polishing
I don’t have a quantitative test for grindability. Reports from knifemakers so far say that grinding and polishing is very easy with the steel. Some low alloy steels developed for higher wear resistance like CruForgeV are more difficult to polish due to relatively large vanadium carbides that are found relatively frequently. This steel we controlled the W/V content to try to avoid large carbides. Because of the limitations of standard steelmaking (as opposed to powder metallurgy) there are still very occasional larger carbides but they are much rarer than a steel like CruForgeV. So far those few carbides don’t appear to be affecting polishing and finishing.
A lower magnification image of ProCut showing that large carbides aren’t observed most of the time
One of the rare large carbides in ProCut
A micrograph of CruForgeV showing large carbides. Notice there is a magnfication difference vs the ProCut images.
Quenching, Oil Selection, and Hamon
The “hardenability” of ProCut is relatively high, which I also found in testing of 15N20. The high nickel content gives it this hardenability. Air cooling from 1600°F with 1/8″ steel resulted in 60.7 Rc, though from lower temperatures like 1350°F the hardenability is lower (I measured 35.3 Rc). This means that ProCut can be quenched in virtually any quenching oil, even canola, and with relatively thick cross-sections.
This high hardenability means that ProCut is not well suited for developing a hamon. The best choices for a hamon are low hardenability steels like 1095, W2, and 26C3. I won’t say it is impossible to develop a hamon but there are better choices. It is likely still fine for other differential methods like an edge quench.
Forging, Thermal Cycling
Maximum forging temperatures are most greatly affected by the carbon content. High carbon steels are easier to overheat, leading to crumbling while forging. The carbon content of ProCut is limited to ~0.87% so this is not a huge factor with ProCut. For safety I put in the datasheet to limit forging to 2200°F (1200°C). Some knifemakers, especially Damascus makers, push the boundaries of forging temperatures and this can be dangerous. Like with other steels, if you continue to forge when the steel gets too cold this is also a danger in terms of cracking. I haven’t heard a lot of feedback in this area so let me know how the steel behaves for you. The high hardenability means that the steel can sometimes harden in air while cooling from the forging temperature. This can lead to cracking if there are stress risers in the blade.
The “thermal cycling” procedure for ProCut is relatively simple. Like with other steels I prefer to do a single normalize and anneal, so only two steps. I have written about this procedure in past articles. The normalizing step is for dissolving any undesirable carbides and other structures. For this steel it would be in the range of 1600-1650°F where the cementite is dissolved. With a furnace you can hold at this temperature for 10-15 minutes before air cooling. With a forge by eye you just need to heat somewhere into that range or a bit higher.
The annealing procedure is then done by heating to nonmagnetic and slow cooling. I recommend faster cooling rates than is typical for datasheets and this type of anneal is called a “Fast DET” anneal. For simple heat treatments you can slow cool either in a furnace or in an insulating media like vermiculite (available in the garden section of home improvement stores). I tried a range of cooling rates in my furnace. I held the steel for 30 minutes at 1350°F and slow cooled at different rates to measure the annealed hardness. At 50°F/hr cooling the resulting hardness was 23.9 Rc. After 500°F/hr the hardness was 24.5 Rc. I also tried setting the furnace to 1000°F/hr but it only maintained that cooling rate until about 1250°F and slowed from there, the average rate of cooling was about 680°F/hr. That resulted in 26.2 Rc, which is plenty soft enough. Shawn Houston did an anneal with 250°F/hr and he measured 21.2 Rc. Here is the microstructure after normalizing and annealing at 1350°F for 30 minutes, and cooling at 250°F/hr:
Normalized and “Fast DET” annealed microstructure of ProCut (21.2 Rc)
“As-received” annealed microstructure of ProCut (12 Rc)
You can see that the faster annealing procedure results in a finer microstructure which is why the austenitizing response was different (see the prior as-quenched hardness chart). The toughness was still relatively similar despite the very different starting microstructure (see the toughness vs austenitizing temperature chart). Those datapoints were generated using a 100°F/hr anneal which is what I recommended in the datasheet. Somewhat faster and slower cooling rates would have a similar result.
Use in Damascus
The high nickel content means that ProCut is a good replacement for 15N20 or L6 as a bright layer in pattern-welded Damascus. This gives an option for providing higher edge retention whereas 15N20 and L6 have almost no wear resistance apart from their hardness. An initial forging experiment with 1084 and ProCut resulted in excellent contrast:
Edge Retention
Pop’s ProCut did surprisingly well in the CATRA test. The heat treatments performed were 1650°F with a 450°F temper (61.2 Rc), and 1500°F with a 300°F temper (64 Rc). As I have written about before, CATRA is not the best for low alloy steels because the sand particles in the test media are harder than cementite (iron carbides). Even with different media they wouldn’t be at the top of the chart but they would be a bit better. It could be that the relatively low amount of cementite in ProCut helped for the CATRA test. But even if that were the case if we compare with another steel with low cementite content like 8670 or 1095, there was a significant boost to edge retention through the tungsten and vanadium additions. Perhaps with the lower carbon compared with other W/V steels meant that there was less of tungsten and vanadium found in the cementite, allowing them to form more of the hard WC and VC carbides.
Toughness-Edge Retention Balance
With the high toughness plus the unexpectedly good CATRA numbers the ProCut looks very good compared with other low alloy steel options:
Corrosion Resistance
This is a non-stainless steel and should not be expected to be stainless. People say that the 2% nickel in 15N20 gives it somewhat better corrosion resistance than carbon steels but I have not developed a test for comparing corrosion resistance of low alloy steels.
Cryo
There is a certain lore out there with knifemakers claiming that some steels “need” cryo and other steels “don’t benefit” from cryo. Part of this lore is that low alloy and carbon steels are in the “don’t benefit” category. Simple carbon steels and low alloy steels still see an increase in hardness with cryo, typically 0.5-2 Rc depending on the steel and the heat treatment. There is a small cost to toughness because of the increase in hardness. ProCut is the same. As an example of another low alloy steel we experimented with see 52100. I did experiments from 1500°F and 1650°F and found, as expected, that hardness increased. The higher temperature led to a bigger bump from cyro which is also typical. None of the edge retention or toughness tests I showed in the article so far used cryo in any of the heat treatments. But if you want even higher hardness for edge retention and strength you can add a cryo step after quenching.
Comparisons to Other Steels
1084 and 15N20
These steels are relatively “easy” to heat treat in that you can heat them up and quench them and get full hardness. However, they are very easy to overheat leading to grain growth and a drop in toughness. They also have almost no carbide thus having very little wear resistance.
80CrV2
This steel is also lacking in wear resistance though overheating is not much of an issue because of the vanadium addition. It also varies a lot between manufacturers and needs more temperature prior to quenching making it more difficult to perform a forge heat treatment.
52100
In the lower austenitizing range (for higher wear resistance), ProCut compares favorably with 52100 in terms of properties. 52100 has a very good combination of toughness and wear resistance. ProCut is easier to heat treat for an amateur knifemaker and also has the option of the high toughness heat treatment.
O1 and 1095
These are old standard steels. O1 has the benefit of being “oil hardening” so it is easier to quench. I have found both to be very sensitive to overheating because of excess carbon in solution. See my article on O1.
5160, 8670, and L6
These steels have significant chromium additions so they are more difficult to heat treat in a forge. They also don’t have any carbide left over after heat treating and thus their wear resistance is very low.
Blue #2, Wolfram Special, 1.2519
These steels have similar wear resistance for edge retention but significantly lower toughness and do not have the benefits of being beginner friendly.
ApexUltra
This is another low alloy steel I helped develop. It has significantly higher wear resistance and attainable hardness than ProCut, which also means lower toughness. I would recommend ApexUltra for those looking for maximum performance in the “carbon steel” category. Though I wouldn’t call it a difficult steel, it is best for makers that have a bit of experience first.
Heat Treatment Recommendations
In a Forge
Heat to “one shade brighter” after reaching nonmagnetic, quench in oil (most types are fine), and temper twice for one hour each time at 300-450°F (150-230°C) to desired hardness.
In a Furnace
Maximum toughness: 1650°F (900°C) for 10-15 minutes.
Higher edge retention: 1500°F (815°C) for 10-15 minutes
Quench in oil (most types are fine), and temper twice for one hour each time at 300-450°F (150-230°C) to desired hardness.
Thermal Cycling after Forging
1625-1675°F for 10-15 minutes, air cool. Without a controlled furnace, heat into that rough range and establish an even temperature distribution prior to cooling.
1350°F for 30 minutes, cool at 100°F/hr to 1100°F. After that it can be cooled more rapidly. Without a controlled furnace, heat to nonmagnetic and slow cool such as in vermiculite.
Summary and Conclusions
I am happy with how Pop’s ProCut turned out. It offers good balanced performance when compared with other low alloy non-stainless steels. Better edge retention than 1095, O1, 80CrV2, L6, 15N20, etc. And depending on the heat treatment its toughness approaches 8670, 15N20, and 5160. And on top of this it is beginner friendly, being easy to heat treat, grind, and finish.
Fantastic. I’m interested in giving this a shot in woodworking plane irons. Will track down on the pops site.
Intriguingly, Sandvik produce many powdered steels (under their Osprey brand), and one of them – 4365 contains 1.65 – 2.00 % nickel.
Carbon 0.62 – 0.66
Chromium 0.7 – 0.9
Nickel 1.65 – 2.00
Molybdenum 0.2 – 0.3
Silicon 0.15 – 0.3
Manganese 0.6 – 0.8
I wish it had 1.65 – 2.00 % Silicon which would increase it’s resilience and springiness, especially with a lower bainite producing heart treatment.
Larrin – second comment. I have gone to quenching in brine for most things, but I don’t use oil hardening or air hardening steel. 52100 gets divine results for woodworking chisels if it is brine quenched, and same for gravers (to stitch rasps).
I’d be interested in a little side study at some point of the effect of a brine quench and freezer vs. an oil quench and cryo. You tested my original samples of 26c3 out of parks 50 from a forge. Brine quench for woodworking tools allows me to get a point higher in hardness, at least, and still smaller grain than back at that point by snapped samples viewed under a scope. I’ve got a dewar, but have never bothered to fill it because it seems like the gap between my hardness and your cryo hardness disappeared once I started brine quenching the water hardening steels.
It could crack this alloy, but I have my doubts that it will. The brine part is important – plain water is disastrous.
Another exciting new development! Are the TCC/Hardness and Toughness/Edge Retention charts showing the higher or lower heat treatment (and what are the results for the other heat treatment)?
The CATRA results chart has both, the heat treatments are given in the paragraph next to it.
I’m sorry, I only see one line on the graph under the Edge Retention heading and one point on the point under Toughness-Edge Retention Balance. Am I missing the other points?
That isn’t the CATRA results chart, that one only has the high toughness condition on it.
I see now, thank you!
This looks like a candidate to give us more knives like the old Sabatiers that so many who had them Came to appreciate.
Great news! That’s a very interesting alloy for quite a lot of uses, well done.
Larrin, how much carbon do you calculate each variant of the solution does have once the steel is tempered?
I’ve made 2 small kitchen knives, high hardness and high toughness. I plan on giving to the wife to test as she is hell on knives.
Larrin, third comment – apologies, but of your efforts so far, I’m enamored with this one as it’s the first simple steel that has minimal foreign carbides in it and a decent hardness.
So here’s my question: is there a concession for having the nickel in the steel. I see that it helps dislocations occur without catastrophe coming with them to an extent and prefers to general avoid any formation (carbides, etc).
My question is based on the higher carbon steels like 26c3 and other things of the like in the territory of files and razors. Would addition of nickel to those sacrifice edge strength or stability in some way? in the world of tools, lack of deformation or chipping at the edge – either one – is better than anything else. We are not particular about toughness to a point (very low toughness steels are no good, but other than that), but edge stability and strength rule. Does nickel change yield strength (is there a concession of strength to get the ability to move without breaking?), or is it possible in something like 26c3 *plus* nickel, additional toughness could allow a harder temper without brittleness?
This is great, thanks for the post, and I also liked Ericasedc’s video on knives made from this.
Can you say what is happening with ApexUltra? Was there ever a production run and is it available anywhere, or will it show up again? I’m told that none of the vendors listed on its web site have it any more.
Congratulations on another mile stone.
Another presentation prominently involving a nickel addition. I wonder if adding nickel to magna cut would increase toughness or whether that would mess up the chemistry you so carefully developed.
I would love to see you do your standard testing on Sharon Steel 0170–6 otherwise known as CroVan, carbon V etc. There is an older formulation with a nickel addition, and a newer formulation without nickel, and it would be interesting to see both. Although with everything you’ve got on your plate, presently, it might be hard to get around to. There are a lot of people using older knives with this steel and there are still companies using the newer formulation. I think this comparison would be interesting to your ever-growing readership.
Hey Larin, great info and thanks for all your work. Can you define dangerous in your discussion on forging temps? Are we talking just cracking/crumblining or worse? Thanks.
Cracking and crumbling is what I meant
Hello. We acquired some Procut and started working with it just last night. An observation is that ours did not spark much on the grinder like other high carbon steel. Is this a quality you observed?
I have heard that from at least one other knifemaker but it isn’t something I have been paying attention to. Both nickel and tungsten are known to have a relatively strong effect on sparking behavior so it wouldn’t be totally unexpected.
I’m getting 67/67.5 hardness as quenched out of brine (three different samples):
https://imgur.com/opp7rud
Snapped sample at 50x optical, generally as fine of a snapped sample grain as I’ll see. Steel as delivered, heated to near scale twice, then quenched just before magnetism returns (brine) and a set of thermal cycles following that in an induction forge, and then a pushed heat.
Very forgiving. Reminds me of 80crv2 to some extent, which needs to be pushed in a quick heat much more than 1084.
I’m waiting until tomorrow to temper a plane iron that also tests 67/67.5. Behavior out of a brine start, and then aluminum plate finish is very good, on par with oil hardening steel. No cracks.
Fantastic. It’s always interesting to see how you combine all the aspects you learn from other steel formulations from your testing into one best compromise point for a new knife steel.
You’ve made one of the best super powder metallurgy steels, and now this, the super hard to mess up carbon steel. I hope it explodes in popularity to compete with 80Crv2, since it’s got even better properties and I hope you can get it melted and rolled for relatively inexpensively for broad appeal.
The toughness to hardness and wear resistant balance you do such a good job to maximize.
You’re such a gift to the knife community and just keep on giving.
Insane results. I didn’t think there was much space for improvement for this kind of steel but the results are so dominant as to be almost too good to be true.
The versatility from the high toughness or high wear resistance heat treat options is unreal. We exclusively forge, making large chopping/hard use blades from 5160 and are swapping to 80crv2 as we’re aiming for higher edge stability to permit finer edge geometry. Part of the rationale is that it will perform ~slightly~ better in wear resistance for less chopping focused knives also.
The notion that we could swap to a single different steel, switch up the aust temp and get such a performance jump for either of these opposing performance demands is unreal. Massive upgrade in capability with a streamlined workshop and simple bulk buying. For us (a tiny minority) a thicker stock than what’s currently available is essential- however I’m sure this will come in time when ProCut inevitably takes the world by storm.
Take care,
Andrew and the team at Kailash
>>Insane results. I didn’t think there was much space for improvement for this kind of steel but the results are so dominant as to be almost too good to be true.<<
those of us who like relatively plain steels have been neglected for a long time. Larrin could carve out a big dent here, but the market is not so sexy. Too bad.
I'm still curious (Larrin?) about whether or not an addition of nickel to something like 26c3 (and less tungsten than pro cut) would improve the toughness and strength. Basic scuttle that I read on nickel is that it improves both yield strength and toughness (I forget about tensile strength). Is there a drawback if carbon is in greater supply and tungsten cut back so that there isn't a problem with larger disparate carbides? Or even just a nickel addition alone?
The toughness improvement for ProCut is relatively small until most of the carbides are gone (high austenitizing temperature). So presumably the nickel isn’t helping too much while carbides are the limiting factor. This would also be the case for 26C3.
Thanks for the clarification, Larrin. Makes sense, which makes it not make as much sense for steels (26c3 in this case) that have a lot of carbon tied up in iron carbides, so much so that trying to get most of it into solution could or would likely yield very unflattering results that negate the benefit of the nickel in the first place.
As it is suitable for forging into “Damascus” patterned objects, I assume it would also be suitable for forging into the cutting edge in a 2 or 3 layered laminated cutting tool such as a nata style forestry hatchet?
I did not see shock resistance called out specifically, I assume the “high toughness” quench & temperature regimen would give the best shock resistance for a “chopping” woods tool?
Shock resistance is not a materials engineering term. I don’t know how it would differ from impact toughness.
What’s the range on the composition? Or has there only been one batch and that’s the measured content?
Looks like a really nicely balanced steel
Do you have any further data about higher temperature tempers using the higher toughness (1625F austenitize)? I notice on the chart that using the 1550 austenitize drops in toughness when pushing past 450F temper, due to tempered martensite embrittlement. Is the same behavior seen in the higher toughness heat treatment?
It would likely be the same
In your recent article about 3v you did a new experiment concluding that the transverse and longitudinal toughness were both very good because of fine grain structure and low carbide volume. With the fine grain structure and even lower carbide volume, would Pops procut be expected to also exibit very close transverse and longitudinal toughness values?
I didn’t test it so I couldn’t say so definitively
What are your thoughts on using this steel with CruForgeV in Damascus? I notice you said a number of times the carbon is very specific. With CruForgeV having a higher carbon content could/ would there be issues with carbon migration?
CruForgeV would work great
Quick question Larrin. How would this steel work with differential hardening? Clay coated spine. Would it be a better practice to differentially temper it instead of the clay coat? Drawing the spine back with a torch instead of. I’m not looking for a Hamon, I’m just liking the toughness increase I can potentially get! Higher hardness edge with a spring tempered spine, would make a great wilderness survival/hunting knife. Thanks
If it were me I would try edge quenching or drawing the spine back with a torch.
I have a question about the differential tempering process that has long vexed me. The process of drawing the hardness back with a torch, is often called “blue backing”, because the spine is heated until blue, which is 575F, which is right in the middle of the tempered martensite embrittlement range for a lot of steels. For most knife making steels the tempering temperature you recommend is usually around 400F, because most steels enter the TME range shortly above 400F. In order to have any gains in toughness from differential tempering, would the tempering temperature for the spine not have to exceed the TME range?
Steel temper color chart link: https://knifemaking.com/pages/forging-steel-heat-color-chart?srsltid=AfmBOopUsE-QGNY5_gXdExm_SPxxI70eNC5p94YiKpkpbKXNYne3GqN7
Toughness does go up again if you temper hot enough, though I agree that 575°F is likely to still be in TME. You would likely still gain some ductility by softening the spine though toughness would not be improved if you only went up to 575°F. Here is a picture of actual steel samples with different temper colors (though remember this is for carbon steels and some low alloy steels only): https://en.wikipedia.org/wiki/Tempering_%28metallurgy%29#/media/File:Tempering_standards_used_in_blacksmithing.JPG
Larrin – I’ve made two santoku knife blanks out of pro cut, and several woodworking plane irons.
I did a couple of these in parks 50, but out of a forge, I just always get better results with brine, and 10% brine has quenched the top end of these (two seconds) and then into plates into a super result.
67 or a half point higher in every case out of the quench, no sign of grain growth even at high magnification and 63/64 range hardness after tempering the knife blanks at 375 in two tempers. Cracking is always a chance with things, obviously, but my experience is this steel likes brine – so far. From the perspective of a guy who mostly uses induction forges or for knives sometimes finishing the tail of the heat in a narrow diameter high heat forge (two mapp torch), brine is nice. I get it that it’s too risky for a lot of pro makers, but it really seems to bridge a lot of the gap between no cryo and cryo without the intermittent hardener having to keep and deal with dissipating LN.
I had no intention really of making knives, but conversation of the steel among a pair of woodworkers came up with a knife request and when one likes something, the other immediately requests a copy.
What would be your recommendation for a higher performing “dark layer” to pair with pro cut for pattern welded steel? My first thought is cruforgev but i can’t find a source for it. Do you have another suggestion?
I will be covering this more in the coming months. There are many that work. For commonly available steels, 80CrV2 would be the simplest and easiest which would also provide relatively high toughness. For higher edge retention you could try 52100 though it is trickier to forge weld. There are also many tungsten alloyed steels (and CruForgeV as you mentioned) though not as widely available.
I am curious if there is any performance benefit by austenitizing at the lower temperature range. Am I correct in thinking the edge retention property follows the same curve regardless of austenitizing temp but more toughness can be gained from the higher austenitize for a given hardness? The lower temperature seems beneficial if forge heat treating and for damascus compatibility but is there a scenario where the lower range would be preferred if using monosteel procut in a kiln?
There is more carbide for edge retention when using the lower austenitize. So for the same hardness it would have somewhat higher wear resistance and edge retention.
Dr. Thomas, I am sorry for the ingnorant question. I am just a hack that enjoys making some knives every now and then. For your Pop’s Pro Cut steel, when I send it to Bos heat treat what is the ideal hardness desired HRC for the heat treat?
Thank you and have a great day.
Jay