FGH96粉末涡轮盘结构模拟件疲劳小裂纹扩展试验  

Fatigue Small Crack Propagation Test of FGH96 Turbine Disc Structure Simulation Specimen

作　　者：赵作鹏 胡绪腾[2,3] 郭秩维 温卫东 ZHAO Zuo-peng;HU Xu-teng;GUO Zhi-wei;WEN Wei-dong(College of Mechanical and Electrical Engineering,Sanjiang University,Nanjing 210012,China;College of Energy and Power Engineering,Nanjing University of Aeronautics and Astronautics;Key Laboratory of Aero-Engine Thermal Environment and Structure,Ministry of Industry and Information Technology,Nanjing 210016,China;AECC Shenyang Engine Research Institute,Shenyang 110015,China)

机构地区：[1]三江学院机械与电气工程学院,南京210012 [2]南京航空航天大学能源与动力学院 [3]航空发动机热环境与热结构工业和信息化部重点实验室,南京210016 [4]中国航发沈阳发动机研究所,沈阳110015

出　　处：《航空发动机》2024年第2期83-87,共5页Aeroengine

基　　金：江苏省高等学校基础科学(自然科学)研究项目(23KJB460026)资助。

摘　　要：为了分析涡轮盘轮缘榫槽等几何不连续部位对疲劳裂纹萌生及小裂纹扩展行为的影响,基于FGH96粉末盘实际构型设计结构特征模拟件,并对其在高温条件下开展自然萌生疲劳小裂纹扩展试验,通过疲劳中断试验和表面复型技术对榫槽和螺栓孔结构模拟件在500℃下的裂纹萌生和小裂纹扩展行为进行了观测和分析。结果表明:2种结构模拟件缺口表面存在多裂纹萌生现象,随着应力水平的降低,裂纹萌生位置由表面晶界转变为近表面特定方向的晶面以及非金属夹杂物处;2种结构模拟件裂纹萌生寿命占比约为36%~73%,且随着应力水平的降低而提高,裂纹扩展至工程可检裂纹尺寸时的寿命占比约为82%~96%,应力水平对其影响相对较小;特征模拟件缺口附近高水平的塑性变形能够导致小裂纹扩展速率分段特征现象消失,并延缓裂纹扩展过程中的合并行为,延长裂纹扩展寿命。In order to analyze the influence of geometric discontinuities(mortise and groove,etc.)of turbine disk rim on fatigue crack initiation and small crack propagation behavior,a structure characteristics simulation specimens were designed based on the actual configuration of an FGH96 powder disc,naturally-initiated small crack propagation tests of the specimens were carried out under hightemperature conditions.The fatigue crack initiation and small crack propagation behaviors of the mortise and groove and bolt-hole structure simulation specimens at 500℃were observed and analyzed by fatigue interruption tests and surface replication techniques.The results show that there are multi-site crack initiation phenomena on the notch surface of the two structural simulation specimens.With the stress level decreases,the location of crack initiation changes from surface grain boundaries to near-surface specific crystallographic facets and non-metallic inclusions.The crack initiation life accounts for about 36%to 73%of the total predicted fatigue life for the two kinds of structure simulation specimens,and increases with the decrease of stress level.The crack initiation life is about 82%to 96%of the total predicted fatigue life when the crack propagates to the detectable size,and the influence of stress level is relatively small.High-level plastic deformation near the notch leads to the disappearance of the segmented characteristics in the small crack propagation rate,and delays coalescence behavior during crack propagation,extending the crack propagation life.

关 键 词：FGH96合金 结构模拟件 疲劳小裂纹 裂纹萌生 裂纹扩展 涡轮盘 

分 类 号：V231.95[航空宇航科学与技术—航空宇航推进理论与工程]