TY - JOUR
TI - The thermal history and stress state of a fresh steam-pipeline influencing its remaining service life
AU - Bakić Gordana
AU - Šijački Žeravčić Vera
AU - Đukić Miloš
AU - Maksimović Stevan M
AU - Plešinac Dušan
AU - Rajičić Bratislav
JN - Thermal Science
PY - 2011
VL - 15
IS - 3
SP - 691
EP - 704
PT - Article
AB - The service life of thick-walled power plant components exposed to creep, as  is the case with pipelines of fresh- and re-heated steam, depend on the  exhaustion rate of the material. Plant operation at elevated temperatures and  at temperatures below designed temperatures all relates to the material  exhaustion rate, thus complicating remaining life assessment, whereas the  operating temperature variation is a most common cause in the mismatching of  real service- and design life. Apart from temperature, the tube wall stress  is a significant variable for remaining life assessment, whose calculation  depends on the selected procedure, due to the complex pipeline configuration.  In this paper, a remaining life assessment is performed according to the  Larson-Miller parametric relation for a Ø324×36 pipe bend element of a fresh  steam-pipeline, made of steel class 1Cr0.3Mo0.25V, after 160 000 hours of  operation. The temperature history of the pipeline, altogether with the pipe  bend, is determined based on continuous temperature monitoring records.  Compared results of remaining life assessment are displayed for monitored  temperature records and for designed operating temperature in the same time  period. The stress calculation in the pipe bend wall is performed by three  methods that are usually applied so to emphasize the differences in the  obtained results of remaining life assessment.