柴油机排气阀阀杆频繁断裂的分析与处理

Analysis about a failure of which diesel exhaust valve's stem frequently broken

船用柴油机的排气阀,大多采用高合金耐热钢制造。排气阀长期工作在高温及腐蚀的恶劣环境下,所以排气阀主要的失效形式有气阀头部宏观裂纹、烧蚀掉块破碎和气阀杆身断裂等。本文介绍了柴油机排气阀阀杆频繁断裂故障的分析和处理过程;探讨了各种可能的故障原因;主要从失效零件宏观形态与材料的断裂方式2个方面进行分析,找出气阀断裂原因。通过故障的实际解决过程,找出处理方法及预防措施,同时为故障原因提供可靠的证据;从而为船舶管理人员提供维修保养经验,保证船舶安全运营。

Most of the marine diesel engine exhaust valves are made of heat-resistant and high-alloy steel.Because exhaust valves work in high-temperature and corrosive environments,the exhaust valve failure forms are macro-crack of the valve head,ablation block broken off and the valve stem broken.The paper analysis about a frequent failure form of the diesel engine exhaust valve stem and investigate the various possible failure causes and the causes of valve fracture.The causes of valve fracture are found out through the two aspects analysis of the main macro-morphology and the fracture mode,and the paper gives the treatment methods and precaution.The failure of reliable evidence are given by the failure of actual settlement process.The paper provide repair and maintenance experience for managers to ensure the safe of ships.