服役环境对汽轮机低压转子30Cr2Ni4MoV钢力学性能的影响  

Effect of service environment on mechanical properties of 30Cr2Ni4MoV steel for turbine low-pressure rotor

作　　者：李彦国[1] 胡正飞[1] 赵双群[2] 

机构地区：[1]同济大学材料科学与工程学院,上海200092 [2]上海发电设备成套设计研究所,上海200240

出　　处：《金属热处理》2013年第12期1-4,共4页Heat Treatment of Metals

基　　金：上海科委重点项目(09521101305)

摘　　要：对已服役16年的30Cr2Ni4MoV钢汽轮机低压转子的电机低温端和高温高应力段,分别在室温和340℃进行标准断裂力学性能测试。结果表明,长期服役后该转子材料的室温静拉伸性能仍满足标准技术要求。因服役环境的不同,转子两个部位的力学性能有一定差异。高温高应力段材料的低温脆性转变温度明显高于电机低温端,高温高应力段在室温下的延性断裂韧性明显低于电机低温端。两个部位材料的断裂韧性随温度变化的关系也不同,高温高应力段在340℃服役高温下的延性断裂韧性比室温数据略有升高,而电机低温端材料在340℃的延性断裂韧性明显低于室温。基于Paris公式定量分析显示,两个部位的抗疲劳裂纹扩展性能相近,电机低温端的抗疲劳裂纹扩展性能略好于高温高应力段;试验温度范围内,该转子材料的抗疲劳裂纹扩展性能对温度变化不敏感。Standard tests of fracture mechanics properties were carried out for low-temperature end part connected with electric generator and high-temperature-high-stress section of 30Cr2Ni4MoV steel turbine low-pressure rotor which had been in service for 16 years at room temperature and 340 ℃. The results show that the tensile properties of the steel at room temperature are still fully meet the standard requirements. However, there are some differences between the two examined sections for their different service conditions. The toughness- brittle transition temperature of the high-temperature-high-stress section is obviously higher than that of the low-temperature section, and the ductility fracture toughness at room temperature is obviously lower. The relationship between fracture toughness and temperature for the two sections are also different. The ductile fracture toughness of the high-temperature-high-stress section at 340 ~C is a little higher than that at room temperature, but the low-temperature section shows opposite in this case. Quantitative analysis based on Paris formula shows the fatigue crack growth rates of the two sections are similar, despite that the value of the high-temperature-high-stress section is a little higher than that of the low-temperature section. Test temperature has slightly effect on the fatigue crack propagation property under the examined temperature range.

关 键 词：30CR2NI4MOV钢 低压转子 长期服役 力学性能 断裂韧性 疲劳裂纹扩展 

分 类 号：TG142.12[一般工业技术—材料科学与工程]