To characterize the long-term service performance and predict the lifetime of heat-resistant steel applications,more than 300 test pieces can be loaded simultaneously at Baosteel to determine the relationship between stress and rupture duration at specific temperatures. In addition,versatile testing methods have been established that evaluate creep-rupture,stress-relaxation,and creep-fatigue,as well as state-of-the-art tensile testing at hyper-high temperatures exceeding 2 100 ℃. Based on the Larson-M iller method,according to API 530,the accumulation of large volumes of data with respect to stress,temperature,and rupture time of actually tested steels ensures the reliability of predicting the allowable working stress over 100 000 h at any given temperature. For examples,the stress tendencies against rupture time of T/P91 and T/P92 steel tubes,as obtained by Baosteel,are consistent with those from NIMS and ECCC. As an accredited provider of the Proficiency Testing schemes in ISO/IEC 17025 and ISO/IEC 17043,Baosteel has periodically organized national proficiency testing with respect to creep and rupture,thereby providing an efficient way for all parties to assess their technical competence when performing uniaxial creep testing by the methods in ISO 204 and ASTM E139.
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