摘要
对进口的2个X12CrMoWVNbNl0-1-1钢汽轮机转子的T3部位进行了强度考核,并采用光学显微镜(OM)、场发射扫描电镜(FESEM)和透射电子显微镜(TEM)对发生早期断裂和满足强度要求的试样进行了对比研究,分析了试样早期断裂的原因.结果表明:在锻造或热处理过程中,未溶的富Fe、Cr和Nb的第二相大颗粒(Cr16.81Fe76.01Nb5.63Mo1.09W0.36)分布在早期断裂试样的孔洞边缘,是形成孔洞的主要原因,这些孔洞在高温和高应力作用下加速扩展,导致试样早期断裂;M23C6碳化物的粗化导致材料性能下降,是试验钢早期断裂的另一主要原因.
Creep-rupture tests were carried out to samples taken from T3 area of 2 imported X12CrMoWVNbNl0-1-1 steam turbine rotors,after which microstructure examinations were performed to satisfactory and unsatisfactory samples using optical microscope（OM）,field emission scanning electron microscopy（FESEM） and transmission electron microscope（TEM） method,while the examination results compared and the reason leading to the premature fracture of unsatisfactory samples analyzed.Results show that the unmelted coarse second phase particles,rich in Fe,Cr and Nb,found at the edge of cavities in the early fractured sample,formed during forging or heat treatment period,are believed to be the main reasons creating cavities,which then spread quickly under high temperature and stress conditions,and finally result in the premature failure.Coarsening of M_（23）C_6 carbides that makes the material property degraded is considered as the second reason of the failure.
出处
《动力工程学报》
CAS
CSCD
北大核心
2010年第4期298-303,共6页
Journal of Chinese Society of Power Engineering
