"Leo Lichtman" wrote in message
...

"Peter Grey" wrote: I know that as steel (or some steel anyhow) heats,
the surface changes color (clip) Can anyone explain what's happening to
cause this?(clip)
^^^^^^^^^^^^^^^
As the steel is heated, an oxide layer is formed on the surface. Light
falling on the surface is partially reflected from the front of this
layer, and more is reflected from the back of this layer/front of the
steel. If the thickness of the layer is 1/4 wavelength thick, the light
from the front and the light from the back will interfere and cancel. The
eye will then see a color that is the complement of that wavelength. (The
same mechanism produces the colors in an oil slick.)

Thanks. To your knowledge, are there any steels that are more prone to
forming oxides on the surface as they're heated? This is not a structural
application so the mechanical properties of the metal are secondary to its
appearance.

Peter