Carbide coarsening during creep in 12 percent CrMoV steel

Carbide coarsening in a 12% CrMoV steel was studied. Investigations in the gauge length and in the head for both interrupted and ruptured creep specimens tested at an initial stress of 80 MPa at different temperatures and at 600 degrees C at various initial stresses were conducted. The contributions to the rise in strain rate in the tertiary creep were studied in terms of plastic deformation. The rise in strain rate was primarily due to the microstructural degradation by carbide coarsening and the cavitation accumulation.