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Hoosier Musings on the Road to Emmaus

Thursday, November 11, 2004

Beauty is in the eye of the beholder

In the last couple of days, I've had occasion to be harking back to my former life. Once upon a time, I was a steelmaker. My undergraduate degree is in metallurgical engineering, and I spent a few years gainfully employed in the field-- first as a process metallurgist in a manufacturing plant; then as a production metallurgist in a steel mill.

That time often seems to be little related to my current endeavors. The study of theology, scripture and Greek do not have a lot in common with thermodynamics, crystallography or physical metallurgy. But, as my mom used to remind us, there's no such thing as wasted education; and they do find ways to intersect, sometimes in strange and wonderful patterns. It never ceases to amaze me.

For whatever reason, I've found myself referring to that period of my life several times recently: drawing comparisons and finding understanding in one arena, based on the other.

Last night, a late-night mention of the intricacies of Greek grammar (yes, seminarians do this, and some of us even enjoy it!), brought to mind another way that intricacy and complication served to bring some clarity, once I learned to wrap my mind around it. So I thought to share.



What you're seeing here is an Iron-Carbon Phase Diagram: a visual representation of how the crystal structure (and therefore the physical properties and performance) of steel changes, depending on temperature and carbon content. This is the framework-- the grammar, if you will-- upon which steelmaking is based. If you'd like to know more, you can find some explanation, and some useful definitions here.

I don't use it much anymore; but once upon a time, it was part of the fabric of my every day. Isn't it a beautiful thing?

8 Comments:

Blogger Reverend Ref + said...

Aren't "thermodynamics", "crystallography", and "metallurgy" Greek?

November 11, 2004 1:57 PM  

Blogger Jane Ellen+ said...

Maybe so... but still easier than a football diagram. ;-)

November 11, 2004 9:53 PM  

Blogger Beth said...

I think you made Ryan's day with the faulty link on my blog. Phase diagrams are one of the great joys of her life.

November 11, 2004 10:15 PM  

Blogger Dawgdays said...

Yes, it is. I especially like the bit in the upper left corner.

I remember the phase diagram from my one and only materials science class. It reminds me of Feynman diagrams, which are used in physics. To many people, they both look like just so many lines on paper, but if you ken the diagrams, they are both elegant and informative.

In physics, which believes it is on the road to a "theory of everything", these diagrams are widely used to represent what really happens. However, they are just that, representations.

Much the same are our explanations of God. To borrow from a Buddhist proberb, they are not the moon, but a finger pointing at the moon.

(Sorry about the ramble. It happens when I think about God and physics at the same time.)

November 11, 2004 10:49 PM  

Blogger Justin said...

Gawsh!

Reading the comments and looking at the diagrams...I conclude Greek is easier to unerstand

;-p

November 12, 2004 7:38 AM  

Blogger Jane Ellen+ said...

Hey, Shari! I'm delighted to have posted something of which you approve! ;-)

Seriously, let's see if I can answer your questions. Yes, steel is a ferrous-carbon crystalline compound, most often-- though not always-- alloyed with other metals. It's the addition of nickel and chromium, for example, that allows rust-resistant and stainless steels.

Alloys do affect other properties as well: hardness, brittleness, ductility, etc. But those factors also can be controlled, to some extent, by (1) carbon content and (2) heat treatment. More carbon produces a more brittle steel. Above 2% carbon, in fact, it ceases to be called steel, and is instead cast iron, which is very brittle indeed.

As you can see in the diagram, the right combination of factors changes what kind of crystal structure the steel assumes. This is why, depending on the end use, some steel will be quenched-- submerged quickly into water, to "freeze" a given structure in place.

Additionally, steel that needs more flexibility (like your fencing foil)- may be tempered-- held at comparatively low heat for a time, in order to release stresses in the structure that are worked in by processing, which would cause it to snap under pressure. If you've ever bent a coat hangar or a paper clip until it breaks, that's what's happening-- a process is called "work hardening." Stress is being placed in the crystal structure, which becomes then both harder and more brittle, and eventually breaks under pressure.

I think that covers it. Thanks for asking!

November 12, 2004 5:39 PM  

Blogger Reverend Ref + said...

Hey, this is fun. To answer Shari's question on a serious note. I think it's more important for us to be tempered. Still strong in our make up, but flexible enough not to break.

November 13, 2004 8:26 AM  

Blogger Dawgdays said...

Shari, steel can be both quenched and tempered. Strong, tough, yet flexible, not brittle. Just the thing for someone in Holy Orders - or anyone, for that matter.

November 13, 2004 9:47 PM  

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