Ma Longteng, Wang Yanfeng, Di Guobiao
Shougang Research Institute of Technology, Beijing 100043, China.
Materials (Basel). 2018 Oct 24;11(11):2080. doi: 10.3390/ma11112080.
Creep rupture tests of 9Cr-3W-3Co steel were conducted in the range of 120 to 200 MPa at 650 °C. The influence of stress on microstructure evolution was investigated in detail. In the high stress regime, a large density of dislocation was generated and induced precipitation of fine and dispersive particles. However, at lower stresses, a transformation from martensite laths to large size subgrains and a coarsening of precipitates took place due to significant recovery and loss of pinning effect during long term exposure. Thermodynamic results revealed decreasing tungsten content effectively retarded the coarsening behavior of MC₆ and Laves phase, hence further improvement of creep rupture time was achieved experimentally.
在650℃、120至200MPa范围内对9Cr-3W-3Co钢进行了蠕变断裂试验。详细研究了应力对微观结构演变的影响。在高应力状态下，产生了大量位错并诱导了细小弥散颗粒的析出。然而，在较低应力下，由于长期暴露期间显著的回复和钉扎效应的丧失，发生了从马氏体板条到较大尺寸亚晶粒的转变以及析出相的粗化。热力学结果表明，降低钨含量有效地抑制了MC₆和Laves相的粗化行为，从而通过实验进一步提高了蠕变断裂时间。
