H1 Magnetic?

[FLYcrash]

Thanks for the info, BlondeChemist!! Your post inspired me to poke around a little on this topic.

(1) Yes, H-1 definitely is iron-based. The way in which H-1 is impervious to rust (i.e. how it improves on the chromium oxide passivating layer in traditional stainless steels) escapes me. I'd love to learn about that, however...

(2) A lot of complicated and interesting chemistry happens when a iron-based material meets air, water, and/or electrolytes. It's really hard to make generalizations like "pure iron won't corrode." The alloying agents, the type and amount of salts around, the pH, the moisture around, the oxygen fugacity, passivating compounds on the surface...all of this has an impact on corrosion.

Typically both air and moisture is needed to corrode iron or steel. Salts and acid make the process much worse. In dry air, iron will only oxidize to iron(II) (i.e. the iron atoms are missing two electrons). Iron(II) oxides typically stick nicely to the steel, preventing further chemical attack. This, I think, is the basis of the protective dark patina that forms on high carbon steel under normal use. The problem is when both air and moisture are around; then iron can oxidize to iron(III) (three electrons missing), which forms a porous material (rust) that leaves further iron vulnerable to attack.

You could check the Wikipedia article on "rust," which discusses both the redox and acid-base chemistry of rusting and gives an idea of how complicated this business is.

Edit: You beat me to the punch, Zwaplat! That's a cool notion that the nitrogen may actually change the redox properties of the iron. I wonder if that info is in the public domain or is proprietary...where did you learn about it?

[bh49]

Pure iron will not corrode. Iron + carbon combination will.

Sorry for misleading. My statement is not accurate. I should say that pure iron will not corrode as bad as steel with high carbon content.

[BlondeChemist]

That's a cool notion that the nitrogen may actually change the redox properties of the iron. I wonder if that info is in the public domain or is proprietary...where did you learn about it?

Thanks for chiming in guys! I was trying to avoid getting into the nitty gritty, or even mention redox chemistry. I figured it was more info than people really wanted, looks like I was wrong though. :) It is nice to find a forum that actually appreciates technical answers to curiosity questions.
Flycrash, the fact that the nitrogen changes the redox properties of iron is basic chemistry so it wouldn't be proprietary. The exact composition (molar ratios) or the crystal structure of H1 may be proprietary. Keep in mind that even if the composition is available, the heat treating process and finishing will not be, both of which will affect the final state of the surface and edge of the blade.

[Agent Starling]

(2) A lot of complicated and interesting chemistry happens when a iron-based material meets air, water, and/or electrolytes. It's really hard to make generalizations like "pure iron won't corrode." The alloying agents, the type and amount of salts around, the pH, the moisture around, the oxygen fugacity, passivating compounds on the surface...all of this has an impact on corrosion.

I'm no metallurgist, but perhaps a few basic concepts from g. chem. can help clarify things a bit...
When we talk about rust, it's simply the oxidation of iron=iron reacting with oxygen to form a specific iron oxide...

When we're talking about whether a metal is magnetic, as BlondeChemist has stated, the spins of the electrons are involved...basically there were 3 types of metal atoms:

Those that are...

1. Ferromagnetic = a metal that is magnetic = Iron (Fe)
2. Paramagnetic = a metal that is weakly magnetic
3. Diamagnetic = a metal that is not magnetic

Beyond this, when you get into the metallurgy of metal atoms bonded to other things within the steel, crystal lattices, etc., je ne sais pas... :D

Agent Starling

[Zwaplat]

Edit: You beat me to the punch, Zwaplat! That's a cool notion that the nitrogen may actually change the redox properties of the iron. I wonder if that info is in the public domain or is proprietary...where did you learn about it?

I believe sal posted it once. Not sure where tho.

[SimpleIsGood229]

Keep in mind that even if the composition is available, the heat treating process and finishing will not be, both of which will affect the final state of the surface and edge of the blade.

First of all, BlondeChemist, thanks very much for your insight. Secondly, H-1 is precipitation-hardened. As strange a beast as it is, I love it!