H-2 Steel, Knife Steel Nerds Article is Out

[wrdwrght]

I get the austenite transformation. What I don’t get is what happens once Spyderco does the serration. Something happens and I’m not making it up. You’ll have to blame a noted metallurgist for that!

Consider this: viewtopic.php?f=2&t=83847&p=1378907&hil ... s#p1378907

[Matus]

My understanding is that grinding introduces stress / micro fractures / dislocations that increase the strength and thus hardness (BBB will correct me if I got it wrong). This actually also happens with other steels and is part of the reason for cold forging (though I am not sure how much actual effect does it have)

[metaphoricalsimile]

I get the austenite transformation. What I don’t get is what happens once Spyderco does the serration. Something happens and I’m not making it up. You’ll have to blame a noted metallurgist for that!

Consider this: viewtopic.php?f=2&t=83847&p=1378907&hil ... s#p1378907

Nobody is saying you're making it up. What I'm saying is that those results have not been replicated by other researchers that have done similar tests. This happens all the time in science, and is one of the reasons why scientists require replication before taking something as truth. Back when I worked in a chemical engineering lab one of the *first* steps to a a new experiment was to replicate any processes and results that the experiment was expanding on. If those did not replicate we needed to redesign the experiment, and this happened more often than not.

[ykspydiefan]

So, I read this highlighted bit, " They have very high corrosion resistance and excellent formability, and are non-magnetic. The grades are not known for their high hardness, which is generally a requirement for knife steels. Austenitic stainless steels will transform to hard martensite with cold working, however."

Then, I remembered some discussion about working undersea and specialty dive knives being non magnetic. Then, I stuck a magnet on my Pacific Salt H1 and it stuck just fine. Now, I am as confused as I often am. Anyone else try a magnet on their H1?

I guess if any company is going to cater to the, Deepsea Working Corrosion-Resistant Non-Magnetic Dive Knife Market, it would be Spyderco. That part makes sense.

[cabfrank]

Of course I had to try. Seven H1 Salts, all magnetic. What does it mean? I have no idea.

[metaphoricalsimile]

Of course I had to try. Seven H1 Salts, all magnetic. What does it mean? I have no idea.

The purpose of the cold working process is to use physical strain to transform the steel from the non-magnetic soft austenite into the hard martensite phase, which *is* magnetic, so that's evidence that the cold-rolling process did its job.

[cabfrank]

That makes sense. Thanks for the easily understood explanation.

[wrdwrght]

I get the austenite transformation. What I don’t get is what happens once Spyderco does the serration. Something happens and I’m not making it up. You’ll have to blame a noted metallurgist for that!

Consider this: viewtopic.php?f=2&t=83847&p=1378907&hil ... s#p1378907

Nobody is saying you're making it up. What I'm saying is that those results have not been replicated by other researchers that have done similar tests. This happens all the time in science, and is one of the reasons why scientists require replication before taking something as truth. Back when I worked in a chemical engineering lab one of the *first* steps to a a new experiment was to replicate any processes and results that the experiment was expanding on. If those did not replicate we needed to redesign the experiment, and this happened more often than not.

I’m reasonably familiar with the scientific method and how and why contradiction informs it.

Can you point me to the experiments that actually rejected the findings of Crucible’s metallurgist, which so far seem only to be what Sal remembered? I imagine Sal’s understanding is mighty acute given the skin he has in the game.

I would expect that Crucible’s “experiment” would be known to those who have “done similar tests”, but how would they have known of its design?

Or are we simply stuck on variability in the act of measuring hardness(es)?

[JRinFL]

According to Dr. Larrin’s article on H1, he states that Sandvik could not duplicate the results that Crucible achieved. Quoted below.

“I was sent an analysis of H1 in a Spyderco Salt by Sandvik. They did not find an increase in hardness at the edge, in fact they found a decrease. The plot below is what I was sent, where the value at about 55 Rc was 0.4 mm (0.16″) from the edge. Unfortunately I was not provided an x-asis to see the distances between the measurements. However, the ~57 Rc of the steel is comparable to the value reported above from Crucible. It may be that the hardness was reduced at the edge due to overtempering as a result of grinding.”

[Larrin]

I was just sent the Myodo datasheet for H1 which has a couple interesting things in it. For one H1 was developed by Nippon. Typically a datasheet for a steel doesn’t call out the original developer of a grade so this is somewhat unusual. Presumably this means there is a Nippon patent for H1 which might have something interesting in it if we can find it.

Another interesting thing is that a “typical analysis” is given which shows that Myodo had a target Cr of 14.2% even though that is quite low for the specification of 14-16%. That helps explain why Sandvik found only 13.8% Cr in their measurement of H1’s composition. They could have a few different reasons for targeting a lower Cr such as helping reduce delta ferrite or affecting its transformation during cold rolling.

The datasheet also confirms that the values for C, N, Mn, P, and S are maximums as I stated in my articles about H1 and H2.

Myodo also states that H1 is prone to overtempering during grinding, which perhaps explains Sandvik’s reduced hardness value of H1 near the edge. Such effects are why it is difficult to believe that there is actually a hardness increase from grinding operations.

[JRinFL]

My entirely unscientific use of a serrated and non-serrated H1 knives showed no noticeable improvement with the factory edge on SE vs PE. Some mistake the thinner geometry of the SE edge as increased edge holding when really is just the geometry cutting better.

[Wandering_About]

Thanks for the info, Larrin. Seems like H2 will fill its role well enough, to me at least.

[Larrin]

One difficulty with measuring serrated edge retention is they dull much, much slower than plain edges. CATRA has an extended 200 stroke test for serrated edges rather than the typical 60. Even then a VG10 knife I tested basically didn’t dull at all across the 200 stroke test. So just like with plain edges the exact geometry of the serrated edges would be extremely important for the result and would likely wash out steel differences. A more acute angle would win.

[cabfrank]

I think a lot of us freely admitted loving H1, and a lot of us are now realizing we actually did, even though we acted like we didn't. Past tense is premature, of course.

[sal]

Hi All, I guess this is as good a place as any regarding H1, et al; So let's Talk Story:

Back in the day, when Gail and I began making knives, we were sailors and Scuba divers, so there was always the quest for a salt water material that could cut and resist rust.

We tried numerous materials over the years, keeping an open mind. We spent years testing Titanium, Ceramic, and a variety of steel options. We have Military blades that we cast from cobalt, like David Boye's material. Here, I would like to take off my hat to David as he has consistently produced a worthy product. It just wouldn't work out for us and the volume we wanted.

We tried numerous "special" combinations of alloys created by many custom makers. I remember one piece made for me that I was assured that it would be the ultimate material for Salt Water. I remember holding it in my hands as I jumped off the boat and as I was descending, I could see the rust forming. By the time I hit 60 feet, the entire blade had rusted except where my fingers were holding it. Solutions were challenging to say the least.

The first Nitrogen steel was produced by a foundry in Europe. The material was called Cronidor 30. We contacted them and tried to purchase the material, but they turned us down. They said it was for two reasons; 1) We were an international company and they were concerned that we might sell knives with the material to an unfriendly or unethical Country and they might reverse engineer, disregard their patents and breach their patent. and 2) NASA was buying all they could make.

So you can see that we have been chasing this for quite a while. When the Japanese vendors were showing H1 to anyone that would look, we began testing the material. It was a Nitrogen steel. We certainly wanted to make sure that what we offered to our customers did what we said it would do. No hype. No bullshit. Once we were satisfied that we had a material that could serve the need, we jumped on it with all we had. We had go buy a very large amount and we put millions of dollars into promoting the material. While no one seemed to know the "why" and many were skeptical, we forged ahead making models and promoting the material. Needless to say, we have created a market that was happy with what we did.

There were many that kept questioning and testing and dissing, but I think the history over the past 20 years speaks for itself. As I've said, "The edge is a Ghost" and "H1 is the Shadow of a Ghost". While all of the "tech" involving the material has been fuzzy, Gail and I felt getting the material out to serve our customers needs was more important than the "tech".

After Crucible went bankrupt and divided up the company, the (ex) president knew that I had been chasing Cronidor 30. He set up an Import/Export company and since the patent had expired, he made arrangements for Spyderco to receive Cronidor 30, but we had to call it LC (Low corrosion) 200N. As with H1, we did extensive testing to find it's limitations and added it to the Salt series steel stable.

There have been a number of other nitrogen steels developed over the years, but for some reason, we were not able to obtain any, or they were just too expensive to make reasonably priced production knives.

A few years ago, we were informed that Myodo was going to stop making H1. A shock to be sure. Myodo is a foundry that owned by a Korean conglomerate and who knows how far up the line the decision was made. My guess is some "suit" sleeping with "bottom lines" made and implemented the decision. we were not able to find out any information regarding the decision.

At that time, we and our Japanese partners of 40+ years began the search for a company capable of making a steel with the same properties and a rolling mill to roll the material. After much effort, we "created" H2. We did our normal testing of the material and found it to be as good, if not a bit better than H1. I guess we could have just called it H1, but the chemistry was different and we felt it would be deceptive to say it was the same when it wasn't.

Then Larrin's exceptional MagnaCut appeared on the scene. Knowing Larrin, we felt it would be exceptional, so Eric and Spyderco's engineers began extensive testing to find it's limits. The material tested well in accordance with Larrin's findings, but we found the corrosion resistance to be better than Larrin had guessed. So Eric made a very bold move and introduced MagnaCut as a Salt.

I hope the history helps with the understanding. I believe that someday we will learn more than we know today.....but today we are pleased and proud to be able to offer a variety of cutting tools that can handle the challenging needs of the Salt Water environment.

sal

[curlyhairedboy]

Thanks for the background, I had no idea you guys chased Cronidor 30 before H1!

[Deadboxhero]

Thank you for sharing Sal, and Happy Birthday.

This information really helps people understand.

Also thank you all the dauntless effort over the years helping bring the excitement of exotic knife steels to the community.

-shawn

[Larrin]

The day after I posted my H2 article to Patreon Sal was there at Blade at my cryo class which was part of the show. Along with Mike Janich and Eric. Because I had some constructive criticism for the Spyderco Byte I was a bit concerned about what Sal might have thought of it. But I was pretty sure that they hadn’t had a chance to read it yet. Nope, Sal had already read it. I asked Sal what he thought my of my analysis and as his normal gracious self he assured me that he liked the article and wasn’t offended by criticism. Of course anyone familiar with this forum knows that Sal always seems to manage to accept criticism with a smile no matter how harsh. My intention with my article was definitely not to criticize or to generate clickbait and I’m just glad the people running Spyderco take constructive criticism without offense and still remain friends. Which is not always a given in this world. Spyderco had been a big supporter of myself over the years and they are awesome.

[sal]

When Gail and I introduced serrated edges on folding knives in 1982, we knew we had something special. Now, 40 years later, the discussion is still there.

sal

[Wandering_About]

Thanks for the history, Sal. There sure can be lots of business politics behind the steels that end up in our knives, interesting to read of some of it. I for one am glad that LC200N eventually did get into production, as I do like the stuff. I'll admit to having not tried H1, but I do not get into extreme saltwater environments so have not really been motivated to give it a try.