| 摘要 | 第1-12页 |
| Abstract | 第12-18页 |
| Chapter 1 Introduction | 第18-37页 |
| ·Research background and significance | 第18-19页 |
| ·Review of railway axle fatigue | 第19-24页 |
| ·Review of railway axle fatigue history | 第19-21页 |
| ·Review of railway axle fracture behaviors | 第21-24页 |
| ·Summary of the research on railway axle steel | 第24-30页 |
| ·The current application status of railway axle steel | 第24-25页 |
| ·The current research status of railway axle steel overseas | 第25-28页 |
| ·The current research status of railway axle steel in China | 第28-30页 |
| ·The review of very high cycle fatigue research | 第30-34页 |
| ·The contents of this dissertation | 第34-35页 |
| ·Research object and plan | 第35-37页 |
| Chapter 2 Fatigue properties of railway axle steel in VHCF regime | 第37-54页 |
| ·Experimental material and mechanical properties | 第37-39页 |
| ·Fatigue test equipment and method | 第39-42页 |
| ·Rotary bending fatigue tests | 第39-41页 |
| ·Staircase method for fatigue limit evaluation | 第41页 |
| ·Crack propagation rate of railway axle steel | 第41-42页 |
| ·Results of fatigue properties of railway axle steel | 第42-52页 |
| ·S-N curve of LZ50 steel | 第42-44页 |
| ·Staircase test result of LZ50 steel | 第44-45页 |
| ·Crack propagation of LZ50 steel | 第45-46页 |
| ·Fracture surface observations of LZ50 steel | 第46-48页 |
| ·S-N curve of 35CrMo steel | 第48页 |
| ·Staircase test result of 35CrMo steel | 第48-50页 |
| ·Crack propagation of 35CrMo steel | 第50页 |
| ·Fracture surface observations of 35CrMo steel | 第50-52页 |
| ·Discussions | 第52-53页 |
| ·Conclusions | 第53-54页 |
| Chapter 3 Reliability evaluation method for fatigue limit of railway axle steel withsmall sample data | 第54-62页 |
| ·Experimental material and procedures | 第55页 |
| ·Evaluation of fatigue limit for LZ50 steel | 第55-59页 |
| ·Strain-life curve | 第55-56页 |
| ·S-N data transformation process | 第56-57页 |
| ·Evaluation results | 第57-58页 |
| ·Discussions on the evaluation for LZ50 steel | 第58-59页 |
| ·Evaluation of fatigue limit for 35CrMo steel | 第59-61页 |
| ·Evaluation method | 第59-60页 |
| ·Evaluation results | 第60页 |
| ·Discussions on the evaluation for 35CrMo steel | 第60-61页 |
| ·Conclusions | 第61-62页 |
| Chapter 4 Evaluation method of fatigue damage for railway axle steel under variableloading | 第62-72页 |
| ·Materials and experiment procedures | 第62-63页 |
| ·Experimental materials | 第62-63页 |
| ·Experimental procedures | 第63页 |
| ·Experiment results | 第63-66页 |
| ·Results of repeated two-step loading test | 第63-64页 |
| ·Fracture surface observations | 第64-66页 |
| ·Evaluation method | 第66-68页 |
| ·Evaluation results and discussions | 第68-70页 |
| ·Cumulative damage under repeated two-step loading | 第68-69页 |
| ·Influence of loading cycle ratio on fatigue damage | 第69-70页 |
| ·Conclusions | 第70-72页 |
| Chapter 5 Effect of microshot peening on fatigue properties of railway axle steel inVHCF regime | 第72-87页 |
| ·Microshot peening treatment | 第73-74页 |
| ·Microshot peening treatment conditions | 第73页 |
| ·Experiment methods | 第73-74页 |
| ·Material properties after microshot peening treatment | 第74-76页 |
| ·Fatigue properties after microshot peening treatment | 第76-82页 |
| ·S-N curve | 第76-77页 |
| ·Fracture surface observations | 第77-80页 |
| ·SCRS relaxation processes | 第80-82页 |
| ·Discussions of SCRS relaxation process | 第82-85页 |
| ·Quick relaxation process | 第82-83页 |
| ·Slow relaxation process | 第83-85页 |
| ·Conclusions | 第85-87页 |
| Chapter 6 Effect of nitrocarburizing on fatigue properties of railway axle steel inVHCF regime | 第87-119页 |
| ·Nitrocarburizing treatment | 第88-90页 |
| ·Nitrocarburizing treatment methods | 第88页 |
| ·Experiment methods | 第88-90页 |
| ·Material properties of LZ50 steel after gas nitrocarburizing | 第90-98页 |
| ·Material properties of 35CrMo steel after gas nitrocarburizing | 第98-104页 |
| ·Fatigue properties after gas nitrocarburizing | 第104-117页 |
| ·Fatigue properties of gas nitrocarburized LZ50 steel in VHCF regime | 第104-111页 |
| ·Fatigue properties of gas nitrocarburized 35CrMo steel in VHCF regime | 第111-117页 |
| ·Conclusions | 第117-119页 |
| Chapter 7 Effect of gas nitrocarburization on railway axlesteel under axial loading | 第119-130页 |
| ·Experimental material and procedures | 第119-121页 |
| ·Experimental material | 第119-120页 |
| ·Experimental procedures | 第120-121页 |
| ·Fatigue properties of LZ50 steel under axial loading | 第121-124页 |
| ·S-N curve | 第121页 |
| ·Fracture surface observations | 第121-124页 |
| ·Discussions on fatigue strength of LZ50 treated specimens under axial loading | 第124页 |
| ·Fatigue propenies of 35CrMo steel under axial loading | 第124-129页 |
| ·S-N curve | 第124页 |
| ·Fracture surface observations | 第124-128页 |
| ·Discussions on fatigue strength of 35CrMo treated specimens under axial loading | 第128-129页 |
| ·Conclusions | 第129-130页 |
| Chapter 8 Effect of inclusion size on the fatigue strength of railway axles | 第130-139页 |
| ·Experimental procedures | 第131页 |
| ·Experimental material | 第131页 |
| ·Fatigue experiments | 第131页 |
| ·Test results | 第131-133页 |
| ·Fracture surface observations | 第131-133页 |
| ·Inclusion sizes | 第133页 |
| ·Discussions | 第133-137页 |
| ·Inclusion size evaluation of full-scale railway axle | 第133-136页 |
| ·Effect of inclusion size on fatigue strength | 第136-137页 |
| ·Conclusions | 第137-139页 |
| Conclusions | 第139-143页 |
| Acknowledgements | 第143-144页 |
| References | 第144-161页 |
| Publications and research results | 第161-163页 |
