On a recent episode of "factory made" on the manufacture of light rail cars they mentioned that the frames were made of what they called "weathering steel" which was described as an alloy which only develop surface rust which prevents further rusting. If there is such a thing, I'm wondering why they don't use it on automobile frames? What advantages would it have over galvanized steel?
Engineman
It's been around since the 1960s, and the first well-known brand of it was (and is) called Cor-Ten. In the early days it was considered to be a specialty variety of HSLA -- high-strength, low-alloy steel. Today, I think they avoiding classifying it that way.
Sometimes it works; sometimes it doesn't. The big steel sculpture in Chicago, by Picasso, was made out of the stuff decades ago. So are the guard rails on the lower end of the Garden State Parkway. Take a look at some examples and see what you think.
Meantime, Wikipedia has a decent summary of it, plus good links.
In addition to Ed's excellent explanation, Cor-Ten was also used briefly is boat building. Specifically, for rescue craft for the British Life Boat service. What was found was that it was hard to work and resisted shape forming as well as it had very poor fatigue resistance.Continuous flexing caused plate fracture. This would not be a good thing if used in truck frames. It is still used in building construction for external appearance and statues. Steve
John - Rusty Bucket - the old (now gone) total sealed Fab. Fairchild Semiconductor.
There are other examples in San Jose.
It gives a redish rust and it is tough.
Also - the greenish rust on 'Army' rifles is a rust that locks out other versions of rust.
eng> On a recent episode of "factory made" on the manufacture of light rail
Army rifle finish is parkerizing, or properly "Parkerizing", since it is/was a finish of the Parker company. That's a phosphate finish, not oxide, so not "rust".
Stan
we've got some sea going containers that are used for workshop/storage - they've a sticker inside them stating they are made from Corten - now I know a little more about it!
They made Aloha Stadium out of it and found out it doesn't work in Hawaii. Karl
They made Aloha Stadium out of it and found out it doesn't work in Hawaii. Karl
they're replacing corten guardrails in new york (when i saw this article last year i thought "this is a god damned scam, somebody's brother's uncle is a metals distributor and his nephew owns a scrap yard". they're pumping it up in the name of safety so they can blow wads of money.)
By BY MATT KING Times Herald-Record Published: 2:00 AM - 03/18/09 BEAR MOUNTAIN - The metal guardrails along the Palisades Interstate Parkway are supposed to look weathered so as to blend with the views on the scenic byway.
But the job of guardrails is to protect drivers from careening off the road, and the metal rails don't work - at least not as well as they were supposed to.
That's why the state is asking for a total of $121 million in federal stimulus funds to replace rails such as these, which were purchased with an eye more toward form than function.
-snip-
My recollection is that it turned out that Cor-Ten doesn't handle salt well.
Joe Gwinn
It was never intended to. Doesn't stop people from specifying it in the wrong locations though :-(
Mark Rand RTFM
Mark Rand fired this volley in news: snipped-for-privacy@4ax.com:
Like sea shipping containers? Most of them are Cor-Ten steel.
(I missed the beginning of this thread... this may be what it was all about)
LLoyd
"Joseph Gwinn" wrote
I own two forty foot containers that are CorTen. Go figger. Maybe that is why they use them once and then sell them.
Steve
It'll last much better than mild steel, and if paint is scratched, won't undercut so badly. But there's a difference between a container that can be scrapped after 10-20 years and a multi-story building that's a bad bargain if it only lasts 50 :-)
Mark Rand RTFM
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