Creep damage to a steam pipe of an intermediate superheater operating for 90,000 hours

A longitudinal crack appeared in a straight segment of a steam pipeline of an intermediate superheater after operating for 90,000h. The pipeline of 14MoV63 steel with dimensions 609 × 25 mm operated at a temperature of 540°C under a pressure of 18 MPa. We found that its failure is mainly explained by creep. To establish the causes of creep in the straight segment of the steam pipeline, whose predicted service life was 100,000h, we determined the mechanical characteristics of the material and studied its microstructure and fracture surfaces