CREEP-RUPTURE BEHAVIOR OF Ni-BASED ALLOY TUBE BENDS FOR A-USC BOILERS
Advanced ultrasupercritical(A-USC)boiler designs will require the use of nickel-based alloys for superheaters and reheaters and thus tube bending will be required.The American Society of Mechanical Engineers(ASME)Boiler and Pressure Vessel Code Section II PG-19 limits the amount of cold-strain for boiler tube bends for austenitic materials.In this summary and analysis of research conducted to date,a number of candidate nickel-based A-USC alloys were evaluated.These alloys include alloy 230,alloy 617,and Inconel 740/740H.Uniaxial creep and novel structural tests and corresponding post-test analysis,which included physical measurements,simplified analytical analysis,and detailed microscopy,showed that different damage mechanisms may operate based on test conditions,alloy,and cold-strain levels.Overall,creep strength and ductility were reduced in all the alloys,but the degree of degradation varied substantially.The results support the current cold-strain limits now incorporated in ASME for these alloys for long-term A-USC boiler service.
advanced ultrasupercritical cold-work fabrication boilers recrystallization
John Shingledecker
Electric Power Research Institute 1300 West W.T.Harris Blvd.Charlotte,NC,28262,USA
国际会议
Energy Materials 2014(第一届能源材料国际会议)
西安
英文
161-168
2014-11-04（万方平台首次上网日期，不代表论文的发表时间）