超超临界汽轮机转子X12CrMoWVNbN10-1-1钢的早期断裂分析  

Analysis on Premature Fracture of Xl2CrMoWVNbNl0-1-1 Steel for USC Steam Turbine Rotors

作　　者：崔慧然[1] 孙锋[1] 梅林波[2] 张澜庭[1] 单爱党[1] 万荣春[1] 

机构地区：[1]上海交通大学材料科学与工程学院,上海200240 [2]上海汽轮机有限公司工艺处,上海200240

出　　处：《动力工程学报》2010年第4期298-303,共6页Journal of Chinese Society of Power Engineering

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.

关 键 词：X12CrMoWVNbNl0-1-1转子钢 早期断裂 孔洞 M23C6型碳化物 粗化 

分 类 号：TH140.1[一般工业技术—材料科学与工程]