Setting of ultrasonic velocity ratio reference value of P265GH steel for detection of creep degradation by ordinal means of evaluation


Creep is one of the main degradation processes of industrial equipment operated at high temperatures in the power and petrochemical industries. The velocities and ratio of ultrasonic waves are sensitive to changes in stress-strain conditions generated by thermally induced degradation processes. Their utilisation may help with the selection of potentially critical areas on pressure equipment under creep degradation process prior its further investigation by destructive testing. The selection of critical areas is achieved by comparing the tested part with a reference benchmark value. The article proposes a way to set the reference value for conventional pressure purpose steel, such as P265GH and similar, so it can later be used as a benchmark for the selection of critical areas of the equipment in operation.