Analyses on Defect Formation and Damage Behaviors of Main Valves Employed in HTHP Pipes of Thermal Power Plant
Author of the article:XU Hui;GUO Yanjun;LI Xiaohui;WANG Lu;QIAO Lijie;YANG Lin;QIU Zhibin
Author's Workplace：Department of Materials Technology,Huadian Electric Power Research Institute Co.,Ltd.,Hangzhou 310030,China
Key Words：HTHP pipe main valve crack defect stress concentration
Abstract：The service performance of the main valves of the HTHP major pipelines affects the normal operation of the ignition unit of thermal power plant.Various defects of the main valve in service may bring safety risks to the thermal power unit operation.Based on the working principle and service characteristics of four main valves in thermal power plant,the main defect types,formation mechanism and damage mechanism of these valves before and after service were summarized.The effects of various original defects,local stress concentration and microstructure degradation on service performance of main valve were summarized.The common stress corrosion and fatigue failure problems in valves were analyzed and the corresponding control measures were expounded.
