negative temperature in coupled temperature displacement analysis in Abaqus

Hi

I used coupled temperature displacement analysis in Abaqus for simulation hot forming sheet but obtain negative temperature in coupled temperature displacement analysis in Abaqus.

I think maybe my contact or mesh is not correct.

my step type: Dynamic, Temp-disp, Explicit 

mesh type: S4RT

contact type: surface to surface(Explicit) Penalty method contact  with termal conductance

Please help me to solve this problem.