一种700℃超超临界电站用新型高温合金力学性能及高温时效组织性能研究  

Study on Mechanical Properties and High Temperature Aging Structure of a New High-temperature Alloy for 700℃ Ultra-supercritical Power Station

作　　者：曾凡博 李宏 汤云飞 罗煦 夏梦 Zeng Fanbo;Li Hong;Tang Yunfei;Luo Xu;Xia Meng(Baoyin Specialty Steel Tube Co.,Ltd.,Yixing 214203,China;Jiangsu Yinhuan Precision Steel Tube Co.,Ltd.,Yixing 214203,China)

机构地区：[1]宝银特种钢管有限公司,江苏宜兴214203 [2]江苏银环精密钢管有限公司,江苏宜兴214203

出　　处：《压力容器》2019年第12期7-11,共5页Pressure Vessel Technology

摘　　要：通过拉伸试验、硬度试验、冲击试验和扫描电镜(SEM)等方法,研究了一种可能用于超超临界机组的新型Ni-Fe基高温合金在固溶状态下的力学性能及700℃高温短时时效后的组织与性能。结果表明,合金在700℃的强度较室温抗拉强度有一定程度降低,断后伸长率、断面收缩率则无明显下降;700℃高温时效初期,γ′强化相大量弥散析出,材料强度和硬度快速上升,伸长率和冲击吸收能量等指标大幅下降,之后趋于稳定,超过500 h后,随着γ′强化相的粗化和晶界处M23C6等碳化物相析出量增加,强度和硬度开始缓慢下降,塑性和韧性也有进一步缓慢下降的趋势。1 000 h以上长期时效后的合金性能稳定性有待进一步研究。Through the methods like tensile test,hardness test,impact test,scanning electron microscope(SEM),etc.,the mechanical properties of a new Ni-Fe based superalloy which can be used in ultra-supercritical unit,and its structure and properties after short-time aging at 700 ℃ high temperature were studied. Results show that tensile strength of this superalloy decreased to some extent at 700 ℃ high temperature compared with the strength at room temperature,but its elongation after fracture and section shrinkage have no obvious decreasing trend. At the early aging of 700 ℃ high temperature,there was a lot of γ′strengthening phases separating out diffusely,the strength and hardness of this material rose quickly,and the indexes like elongation and impact absorption energy decreased sharply,then they all tended to be stable soon. After more than 500 h,with the coarsening of γ′ strengthening phase and the increase of precipitation of carbide precipitate phase such as M23 C6 in grain boundary area,the strength and hardness begun to drop slowly,and its plasticity and toughness also have a tendency of slowing down further. The properties and stability of the superalloy after long-term aging of the alloy for more than 1 000 h need to be further studied.

关 键 词：Ni-Fe基合金 超超临界 力学性能 组织 

分 类 号：TH142.2[一般工业技术—材料科学与工程] TG146[机械工程—机械制造及自动化]