Mach Stall,
Very nice to have a contribution from someone who understands the thermodynamics. My estimate of 500 degrees was based on my experience that tells me that this is the minimum sort of temperature which will blue steel, particularly over such a short time scale.
For those who are equating this with normal heavy landings, it is obvious that we are talking here of landings which required the undercarriage to be replaced. What other damage may have occurred, I have no idea.