I didn't see the answer to your specific question. The darker area failed in fatigue which took a fairly long time, maybe years. The circular area surrounds the origin of the fatigue crack. The rougher silver area failed in rupture, i.e. all at once. The area that failed in fatigue was exposed to the atmosphere and there surely is some contamination from the environment that it saw. Eric Keller Boalsburg, PA
On Tue, Jan 26, 2010 at 4:55 PM, Rob Hawks <rob.hawks@gmail.com> wrote:
> Hello,
>
> Please take a look at the photos in this blog entry:
> http://449km.blogspot.com/
>
> I'd like your comments on exactly what the darker section on the break
> would mean. The crank in question is a gold anodized Campy NR crank.
> The crank had not seen many miles at all, and had not been abused.
>
> rob hawks
> richmond, ca