CAJ | 학술논문

以一台塔式起重机地脚螺栓发生断裂为案例，从螺栓的热处理工艺、安装工艺、使用工况等方面查找失效原因，用金属构件失效分析理论，采用多种试验验证螺栓的失效过程，再应用宏观检查、微观分析（扫描电镜）研究断面裂纹的形成及发展过程、化学成分分析螺栓材质、硬度试验测试螺栓力学性能、金相分析观察螺栓热处理后的微观组织等，综合分析得出热处理不当是该塔机地脚螺栓断裂的主要原因，为防范类似地脚螺栓失效发生，提出制造、安装、使用环节等建议。
이일태탑식기중궤지각라전발생단렬위안례，종라전적열처리공예、안장공예、사용공황등방면사조실효원인，용금속구건실효분석이론，채용다충시험험증라전적실효과정，재응용굉관검사、미관분석（소묘전경）연구단면렬문적형성급발전과정、화학성분분석라전재질、경도시험측시라전역학성능、금상분석관찰라전열처리후적미관조직등，종합분석득출열처리불당시해탑궤지각라전단렬적주요원인，위방범유사지각라전실효발생，제출제조、안장、사용배절등건의。
With the fact of the foundation bolt of a tower crane subject to breakage as the case,the paper puts forward to find out failure causes for the bolt in aspects of thermal processing technology,installation technology,use condition, etc.With the aid of metal component failure analysis theory,multiple tests are performed to verify the bolt failure process;the macro inspection and micro analysis are employed to study formation of the cross-section cracks and development,with chemical composition analysis for bolt material,hardness testing for bolt dynamic performance,and metallographic analysis for microstructure for the bolt after heat treatment.Through comprehensive analysis,it’s found that improper heat treatment is a main reason for breakage of the foundation bolt.In addition,the paper gives suggestions on manufacture,installation, and service environment in order to avoid similar failure occurrences of the foundation bolts.