材料期刊网

对某电厂超超临界机组运行达到16000 h的新型铁素体耐热钢P92取样管段进行拉伸、冲击性能、断口特征、显微组织、扫描电镜、能谱、碳化物转移、X射线衍射、透射电镜等分析。研究结果表明,P92运行16000 h后室温抗拉强度和规定非比例延伸强度分别达703 MPa和543 MPa,依然保持在较高水平,满足ASME SA335 P92性能要求;高温（600℃）的规定非比例延伸强度值满足GB5310对10Cr9MoW2VNbBN的技术要求;冲击吸收能量在160 J以上,冲击韧性未明显降低;冲击试样的断口显示出韧性断口的宏观特征,纤维区分布着大小相对均匀的等轴韧窝,并且韧窝中存在析出相粒子;析出相主要为M23C6型碳化物,在晶界不断的集聚长大,其次为弥散分布的颗粒状MX相,即Nb,V（C,N）,还含有Fe2W型Laves相,尺寸细小且相对稳定。

Performance and microstructure of a new ferritic heat-resistant steel P92 used in ultra-supercritical unit of Plant for 16000 h was studied by means of tensile and impact tests, scanning electron microscopy (SEM) and EDS analysis, X-ray diffraction (XRD) and transmission electron microscopy(TEM). The results show that the room temperature tensile strength and proof strength at non-proportional extension of the running steel P92 for 16000 h reach 703 MPa and 543 MPa, respectively, which remain at a high level and meet the performance requirement of ASME SA335 P92. The proof strength of the steel at high temperature (600℃ ) still meets the technical requirement of GB5310 for 10CrgMoW2VNbBN. The steel exhibits high impact absorption energy values over 160 J, its impact toughness is not significantly reduced after long-term service. The impact fracture reveals ductile fracture characteristics. Relatively uniform equiaxed dimples, in which precipitation particles are observed, are distributed in fibrous region. Precipitates are mainly M23 C6 carbides along grain boundaries, and dispersively distributed MX phase, Nb, V (C, N) carbides and relatively stable Laves phase(Fe2W) are also observed.