Steel Challenge #1

[Deadboxhero]

Between these two steels, which is more corrosion resistant and most importantly why?

[Spyderwebs]

Fun idea Shawn!

I'm just a guessing layman, but lets see how close I come.

I'm guessing #2 is more stainless, because the Vanadium, Niobium, and Nitrogen allow more chrome to remain in solution, thus adding to its stainlessness.

Close?

[Mage7]

Well, I don't remember for sure, but the one on the left looks like it's close to 400 series stainless steel, 440C by the carbon content? The one on the right looks pretty close to what I have been seeing listed as the composition for MagnaMax.

But outside of just maybe recognizing the compositions, I actually haven't been following MagnaMax's development, so I can only hazard a guess: The molybdenum and niobium will form carbide with all of the vanadium, which helps keep more chromium in the solution because normally chromium will want to form vanadium-chromium carbides. Similarly, the nitrogen also prevents it chromium-iron carbides, further keeping a higher concentration of chromium isolated to provide resistance against oxidation of the iron. If I remember right molybdenum also helps retain hot-hardness and improves grindability, and I think I read niobium and nitrogen both also allows for higher hardness.

I would guess that with 17% chromium the first steel may still be more corrosion resistant than the second because 10-11% chromium just isn't very high. Closer to D2 levels if I recall correctly. Though I think I might have also read that niobium aids in corrosion resistance too, and I know for sure nitrogen does.

Gonna say the steel on the left will still be more corrosion resistant just because of the much higher chromium content.

[Guts]

I'd say 2 because it's the recipe for Magnacut I'm pretty sure. It's more corrosion resistant because magic

[blueblur]

I’m going to guess steel 2, and that the niobium and vanadium take priority over the chromium to combine with the carbon to form carbides.

With steel 1, there aren’t many elements to form carbides other than chromium. If chromium is used for carbides, there will be less free standing chromium for corrosion resistance.

I bet steel 1 is easier to sharpen without high hardness stones (diamond, cbn, etc.).

[Deadboxhero]

Appreciate you guys sharing, let's see if any more people jump in and share their thoughts.

[JFR1]

I'd say 2 because it's the recipe for Magnacut I'm pretty sure. It's more corrosion resistant because magic

This. Better living through chemistry.

Funny how after reading so much about Magnacut over the past couple years we can pretty much pick it out by its composition. I'm curious what steel #1 is. It has a lot of chromium and not much else, so I'm guessing a lot of that goes into chromium carbides.

[p_atrick]

Does Larrin's Knife Engineering book go over alloys and how they keep chromium in solution? I know bits and pieces of information, but clearly not as much as some of you all.

[Deadboxhero]

Does Larrin's Knife Engineering book go over alloys and how they keep chromium in solution? I know bits and pieces of information, but clearly not as much as some of you all.

Tell us what you find.

[Danke]

What thermal process does each steel go through?

[Jeb]

I would say it's #2 and because of that nasty stuff called Niobium and the Nitrogen, which I just love Nitrogen, I give different things around here a bath, slow oozing bath in it while I tig the dang stuff, a gas form, not the liquid lol.

Nitrogen is the magic sauce for me anyway, but I am basically a poorboy(Oldman now) blacksmith want to be lol...

[RustyIron]

Appreciate you guys sharing, let's see if any more people jump in and share their thoughts.

If I was to express an opinion, I would just be parroting what I've read from others. I'm neither a metallurgist nor a chemist. On the left, the chromium would seem relevant to your question, and on the right, the nitrogen would seem particularly important. But that's just a guess, and I would have no independent reason to pick one over the other.

Of course Magnacut has been all the rage recently, so its recipe is recognizable. The one on the left I did not recognize, and I wasn't about to randomly search through recipes. Instead, I fed the data into ChatGPT, and she seems to think it's really close to 440C.

[JARHEAD]

#2 Molybdenum, Niobium, nitrogen. Higher temp for chrome in solution?

[blueblur]

I'd say 2 because it's the recipe for Magnacut I'm pretty sure. It's more corrosion resistant because magic

This. Better living through chemistry.

Funny how after reading so much about Magnacut over the past couple years we can pretty much pick it out by its composition. I'm curious what steel #1 is. It has a lot of chromium and not much else, so I'm guessing a lot of that goes into chromium carbides.

My best guess without looking it up, would be steel#1 is ZDP189.

[Deadboxhero]

What thermal process does each steel go through?

That's a very pertinent question.

Let's assume the Heat treatment is using best practices for corrosion resistance on both.

That would mean you could rule out comparing one in the annealed condition or comparing one that's using an erroneous high temper or no temper.

Given those parameters, which one would you choose for having better corrosion resistance and why?

[Jeb]

What thermal process does each steel go through?

That's a very pertinent question.

Let's assume the Heat treatment is using best practices for corrosion resistance on both.

That would mean you could rule out comparing one in the annealed condition or comparing one that's using an erroneous high temper or no temper.

Given those parameters, which one would you choose for having better corrosion resistance and why?

DBH,

You sir are a freak'n Jeti lol...

[Pacu0420]

This feels a bit like a trick question. Not being a metallurgist, my first guess would be the one with 17% chromium. But, like others have already pointed out, the other looks like the composition of Magnacut. And, if heat treated for optimal corrosion resistance (as DBH stated) I would go with #2. Final answer!

[Danke]

Feels like Magnacut vs. N690 and the nod goes to Magnacut, steel number 2.

[Librarian]

Between these two steels, which is more corrosion resistant and most importantly why?

To answer simply, steel 2 will have better corrosion resistance than steel 1, since the matrix contains more chromium, molybdenum and a little nitrogen (Unless, of course, the PREN index is used to assess corrosion resistance). Of course, provided that the heat treatment took place at the specified austenization temperatures, followed by low tempering and other nuances.

Steel 1

Steel 2

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[Fastidiotus]

This. Better living through chemistry.

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