Thanks for the reply CoryPad. I had that Titanium handbook already - what I'm really looking for is a definitive way I can see if I have an alpha case layer in an area behind a weld. When I inspected the welded area I noticed that the surface on the area behind it was slightly distorted, or rather, the texture of the surface was distorted. I suspect that this area was at a sufficiently high temperature (being right behind the weld area) and outside of the inert gas 'shielding' zone, thus exposed to air. Is there anywhere I could get photo's or microscope shots of alpha case ??
DC.