Talk:Martensite

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Whay austenite density more than martensite?

Update for Martensite Wiki Page

The martensite article needs some overhaul in my opinion, there are poorly worded sections in addition to slight errors. The section "Martensitic Transformation: Mysterious Properties Explained" probably needs the most work. If I get a chance today, I'll rewrite this section.

Spring Steel/Blue Steel

Looking around the web, I find some information about something called "blue (spring) steel". [1][2] I am trying to figure out exactly what this stuff is and what causes the blue color. Spring Steel redirects to here; Bluing (steel) describes a method of chemically treating steel which turns it blue; Blue Steel is a disambiguation page. The Bluing page describes oxide buildup which creates a blue color (Iron(II,III) oxide); the web sites linked above describe a blue surface, among other colors, as a result of tempering at various temperatures. I assume this is due to oxide buildup, but can't find what oxoide (although iron(II,III) oxide seems reasonable), nor can I find an explanation of what makes it blue (I suspect it is interference like the rainbows found on bubbles and oil slicks). Can anyone provide more information? ―BenFrantzDale 01:33, 24 January 2006 (UTC)

Definition of martensite

My textbook offers a completely different definition of martensite: "When a new phase in any (sic) material is produced by a displacive transformation it is always referred to as 'martensite'. Displacive transformations are often called 'martensitic' transformations as a result."(Ashby, Michael F. (1992) [1986]. Engineering Materials 2 (with corrections ed.). Oxford: Pergamon Press. pp. p.74. ISBN 0-08-032532-7. {{cite book}}: |pages= has extra text (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)) Displacive transformations are distinct from diffusive transformation in that they propagate at the speed of sound, even at cold temperatures when diffusive transformation rates are practically nil. Martensite is recognized by the long narrow lens-shaped grain boundaries, as shown in the picture in this article.

This book definition seems much more general than the one used in this article. Most of this article seems to be specific to carbon steel, even going on to talk about body-centred tetragonal unit cells and the like, which is really only a very specific sub-type of martensite which I don't think is actually observed in practice. My book even goes on to point out that "martensite transformations are not limited just to metals. Some ceramics, like zirconia, have them; and even obscure the system of (argon + 40 atom% nitrogen) forms martensite when it is cooled to 30K. Helical protein crystals in some bacteria undergo a martensitic transformation and the shape change helps the bacteria to burrow into the skins of animals and people!"

But I'm really only reading from a single source here. I don't doubt that the word "martensite" is most commonly used in the context of carbon steel. But do you guys think it has effectively been redefined that way by common practice? Should we do a massive rewrite of this article, or just a disambiguation to displacive transformation or martensite (chemistry) or something? Do we need a separate martensite (carbon steel)? Your thoughts, experiences and book quotes would be welcome.--Yannick 05:39, 13 August 2006 (UTC)

I think your definition is probably correct. I put a lot of work into this article some time back, and I must say I'm really happy with the way it reads now. A lot of the language has been tightened up, making the whole thing clearer, more general, and less technical. Kudos!--Joel 21:10, 18 March 2007 (UTC)

Illusion?

From the article: "When viewed in cross-section, the lenticular (lens-shaped) crystal grains appear acicular (needle-shaped), which is how they are sometimes incorrectly described."

Is the article trying to say that the needle-shaped appearance is merely an illusion?? 199.46.240.168 (talk) 21:55, 7 April 2009 (UTC)

Man vs process

Martensite / From Wikipedia, the free encyclopedia / (Redirected from Adolf Martens)

Article has a looping link to Adolf Martens page. Maybe Adolf Martens needs separate short page instead of being redirected to process he invented.

86.38.181.154 (talk) 20:09, 18 January 2011 (UTC)

Restored the article stub for Martins from the redirect. See German Wiki page. Vsmith (talk) 00:24, 19 January 2011 (UTC)