"engineman" wrote in message
...
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.

http://en.wikipedia.org/wiki/Weathering_steel

--
Ed Huntress