高温服役4.2万小时超超临界机组用HR3C钢组织与性能

Microstructure and properties of HR3C steel used in ultra-supercritical units after 42000 h exposure to elevated temperature

采用X射线衍射分析仪、光学显微镜、扫描电镜、透射电镜及拉伸、弯曲力学性能试验对高温服役4.2万小时超超临界机组用HR3C钢的微观组织与力学性能进行了测试表征。结果表明,高温服役后HR3C钢中形成了Cr Nb N,M23C6,Nb(C,N)析出相,受热力学驱动和动力学生长因素影响,各析出相具有不同的数量、形态和分布特征。由于服役过程中形成的析出相的影响,高温服役后HR3C钢塑韧性明显降低,表现时效脆化倾向。

Microstructure and mechanical properties of HR3 C steel used in ultra-supercritical units after 420000 h exposure to elevated temperature were investigated by X-ray diffractometer, optical microscopy, scanning electron microscopy, transmission electron microscopy,tensile test and bending test.The results show that precipitates of Cr Nb N,M23C6,and Nb(C,N) present in the HR3 C steel after exposure to high temperature.Due to the influence of thermodynamic driving and kinetic growth factors,the precipitates show different amount,morphology and distribution.Because of the precipitates form during the exposure to high temperature,the ductility and toughness of HR3 C steel decrease dramatically after serving in high temperature environment,which induces the aging embrittlement.