Microstructure Evolution of a 10Cr Heat-Resistant Steel during High Temperature Creep

Ping Hu 1,2),Wei Yan 1),Wei Sha 3),Wei Wang 4),Yiyin Shan 1) and Ke Yang 1) 1) Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China 2) Graduate School of Chinese Academy of Sciences,Beijing 100049,China 3) School of Planning,Architecture and Civil Engineering,Queen s University of Belfast,Belfast BT7 1NN,UK 4) Electric Power Research Institute of Guangdong Power Grid Corporation,Guangzhou 510080,China

摘 要：The microstructure evolution of a 10Cr ferritic/martensitic heat-resistant steel during creep at 600℃ was investigated in this work.Creep tests demonstrated that the 10Cr steel had higher creep strength than conventional ASME-P92 steel at 600℃.The microstructure after creep was studied by transmission electron microscopy,scanning electron microscopy and electron probe microanalysis.It was revealed that the martensitic laths were coarsened with time and eventually developed into subgrains after 8354 h.Laves phase was observed to grow and cluster along the prior austenite grain boundaries during creep and caused the fluctuation of solution and precipitation strengthening effects,which was responsible for the two slope changes on the creep rupture strength vs rupture time curve.It was also revealed that the microstructure evolution could be accelerated by stress,which resulted in the lower hardness in the deformed part of the creep specimen,compared with the aging part.

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