摘要
采用四点弯曲疲劳试验方法,测试了汽轮机低压末级动叶片05Cr17Ni4Cu4Nb钢焊接接头的疲劳性能,绘制了该接头的S-N曲线,并与钢母材进行了对比。结果表明:采用优化的焊接、热处理工艺,05Cr17Ni4CuNb钢焊接接头的条件疲劳极限可以达到母材的90%以上;焊缝表面或近表面的显微缺陷及接头的组织不均匀性是影响该焊接接头疲劳性能的主要因素,严格控制焊接工艺、减少焊缝显微缺陷、防止热影响区晶粒过度长大是提高叶片焊接接头疲劳寿命的重要措施。
The fatigue property of 05Cr17Ni4Cu4Nb steel(used for the last stage rotor blade of steam turbine)weld joints was studied by means of four-point-bending fatigue test.Moreover,the S-N curve of the weld joints was obtained and compared with that of the parent material.The results showed that,adopting the optimized weld and post weld heat treatment process,the05Cr17Ni4Cu4Nb steel weld joints' conditional fatigue limit could reach 90%of that of the parent metal.The SEM observation of fracture surface of the fatigue specimen indicated that the microdefect in surface or near surface of the weld joints and the microstructure heterogeneity were the main factors affecting the fatigue property of the 05Cr17Ni4Cu4Nb steel weld joints.Thus,several important measures enhancing fatigue life of the weld joints were put forward,such as strictly controlling the welding procedure,decreasing the weld microstructure defects,and preventing the over growth of crystalline grain in heat affected zone.
出处
《热力发电》
CAS
北大核心
2013年第9期108-111,138,共5页
Thermal Power Generation
