700℃先进超超临界锅炉过热器管用新型镍基高温合金GH750的组织和性能研究  

Investigation on Microstructure and Properties of New Type Nickel Base Super-alloy GH750 for Super-heater Tube of 700 ℃ Advanced Ultra-supercritical Boiler

作　　者：赵双群 符锐 林富生 

机构地区：[1]上海发电设备成套设计研究院有限责任公司,上海200240

出　　处：《钢管》2017年第6期5-10,共6页Steel Pipe

摘　　要：GH750是一种我国自主研发的、可以应用于700℃先进超超临界锅炉过热器/再热器管的新型镍基高温合金。研究新型镍基高温合金GH750的组织和性能。研究结果表明:GH750合金的组织由奥氏体基体和强化相γ′,以及微量的晶内和晶界MC、M23C6组成;力学性能优异,室温和高温强度高、塑性好;高温持久性能突出,760℃/10~5 h的持久强度超过100 MPa;在750~850℃高温长期时效后组织稳定性好,无有害相析出;长期时效至10 000 h时,室温拉伸性能变化小,冲击韧性短期下降后趋于稳定。GH750 as domestically developed is a new type nickel base super-alloy for the super-heater/reheater tube to be used for the 700 ℃ advanced uhra-supercritical boiler. The microstructure and the properties of GH750 alloy are studied here in the paper. As a result it is revealed that the super-alloy GH750 consists of austenitic matrix with strengthened phase γ＇, and trace MC and M23C6 as distributed in the grain and at the grain boundary, and has excellent mechanical properties, including both high room temperature strength and elevated-temperature strength, and fine plasticity. The super-alloy also has remarkable hi-temperature stress-rupture, i.e., the 760 ℃/105 h stress-rupture strength 〉100 MPa. And after long term ageing at 700-850 ℃, the alloy still exhibits microstructure stability, and no harmful phases are precipitated. In case of a long term ageing as up to 10 000 h, room temperature tensile property of the alloy is just slightly changed, while its impact toughness trends to be stable immediately after going down for a short time.

关 键 词：锅炉过热器管 超超临界 镍基高温合金 GH750 显微组织 力学性能 持久强度 

分 类 号：TG132.3[一般工业技术—材料科学与工程]