论文部分内容阅读
利用金相显微镜,扫描电镜,能谱仪、透射电镜以及硬度计对国产T23高压锅炉管在服役20 000 h后的微观组织、析出行为以及硬度变化进行了研究。研究发现,服役后原奥氏体晶粒发生回复,导致晶界逐渐模糊;晶界有大量含Cr、W的M23C6型碳化物析出,部分区域的M23C6异常长大,晶粒内有大量MX、VC等相弥散析出,这些析出相与位错相互作用,阻碍了位错进一步扩展,提高了T23钢的抗蠕变性能;T23钢服役后的硬度没有显著变化。
The microstructure, precipitation behavior and hardness changes of domestic T23 high pressure boiler tubes after 20 000 h service were studied by metallographic microscope, scanning electron microscopy, energy dispersive spectroscopy, transmission electron microscopy and hardness tester. The results show that the original austenite grain reverts after service, which leads to the gradual blurring of the grain boundaries. There are a large number of M23C6 carbides containing Cr and W precipitated at the grain boundaries. Some regions of M23C6 abnormally grow up with a large amount of MX, VC and other phases dispersed precipitates, these precipitation phase and dislocation interaction, hindered the further expansion of dislocations and improve the creep resistance of T23 steel; T23 steel hardness after service did not change significantly.