Pascal B steel plate
If the Pascal B steel plate was traveling at 66 km/s, it would have experienced a drag force due to the atmosphere equal to roughly 0.5 x rho x V squared.
https://en.wikipedia.org/wiki/Stagnation_pressure
This is .5 x 1.3 kg/m3 x 66000^2 m/s = 2.8E9 Pa = 475,000 PSI.
This is well above the yield strength of steel at the high temperature created on the plates surface. That temperature is far more complex to calculate because it involves an equilibrium between energy gains and losses and the heat capacities of the materials as they change from solid to liquid to gas to plasma. This is the situation involved in nuclear re-entry and space capsule re-entry and meteor entries into the atmosphere.
A semi-sophisticated ablating vehicle trajectory model was used to model launch of a carbon-carbon plate at 66 km/s at sea level.
This model indicates that the carbon carbon plate ablates about 1 cm every 20 microseconds under these conditions. This is a best case projection that assumes the plate stays intact - which it would not because the stagnation pressure would greatly exceed the yield strength of the carbon carbon.
After 400 microseconds (0.0004 seconds), the ablation depth would be 20 cm ( 8 inches) and the altitude would be about 200 meters. Carbon carbon survives these conditions much better than steel. So the steel plate would evaporate and turn to plasma very soon after launch.
Biting the hand that feeds IT
