CAJ | 학술논문

　　采用激光熔覆技术对磨损失效的Nimonic 80A气门进行修复。利用金相显微镜观察熔覆层组织，用扫描电镜和能谱仪对熔覆层进行组织和成分分析，研究熔覆层硬度的变化，采用渗透探伤检测熔覆层表面缺陷，对合格的再制造气门进行装机考核实验。结果表明：激光熔覆层组织主要由柱状树枝晶和枝晶间的共晶组织组成，熔覆层和基体之间形成冶金结合，熔覆层内部无气孔和微裂纹等缺陷；熔覆层平均硬度较基体提高了37.7%；再制造气门的耐磨性是新气门的1.5倍。
　　채용격광용복기술대마손실효적Nimonic 80A기문진행수복。이용금상현미경관찰용복층조직，용소묘전경화능보의대용복층진행조직화성분분석，연구용복층경도적변화，채용삼투탐상검측용복층표면결함，대합격적재제조기문진행장궤고핵실험。결과표명：격광용복층조직주요유주상수지정화지정간적공정조직조성，용복층화기체지간형성야금결합，용복층내부무기공화미렬문등결함；용복층평균경도교기체제고료37.7%；재제조기문적내마성시신기문적1.5배。
The worn Nimonic 80A valve was repaired by laser cladding. Metallurgical microscope,SEM,EDS and penetrant inspection test were used to analyze the microstructure and composition of the cladding layer. The microhardness of cladding layer was measured by Vicker hardness tester. Meanwhile,the experiment of trial run was conducted with the qualified remanufactured valve. Results show that the cladding layer consists of columnar dendrite and interdendritic eutectic structure. The bond between the cladding layer and substrate is mainly metallurgical,and there are no internal defects,such as blowholes and microcracks,in the cladding layer. The average microhardness of the cladding layer is 37.7% higher than that of substrate, and the wear resistance is 1.5 times greater than that of the new valve.