船用发动机气缸盖渗水原因分析及改进

朱明军¹，倪朝杰^2*，李兵²

1.海军装备部驻上海地区第十一军事代表室，上海  200129；2.沪东重机有限公司，上海  200129

摘要：为解决气缸盖在船用发动机台架试验中出现的渗水问题，采用宏观分析、无损探伤、力学性能测试、化学成分分析、扫描电子显微镜形貌分析、能谱分析和金相分析等系统理化检验手段，分析气缸盖渗水原因，并提出改进措施。结果表明：气缸盖内部存在球化渣缺陷，在发动机台架试验的循环高温、交变应力作用下，部分密集球化渣缺陷相互连接形成贯穿气缸盖壁的通道，是导致船用发动机气缸盖渗水的主要原因；通过改进气缸盖铸造工艺，在成品检验过程中增加气密性试验，可以有效防范气缸盖渗水风险。

关键词：气缸盖；球化渣；理化检验；力学性能分析

Analysis of water seepage causes in the cylinder cover of a marine engine and its improvement

ZHU Mingjun¹, NI Chaojie^2*, LI Bing²

1. The 11th Military Representative Office of the Naval Equipment Department in Shanghai, Shanghai 200129, China;

2. Hudong Heavy Machinery Co., Ltd., Shanghai 200129, China

Abstract: To solve the problem of water seepage in the cylinder cover during the bench test of a marine engine, systematic physical and chemical inspection methods including macroscopic analysis, non-destructive testing, mechanical property testing, chemical composition analysis, SEM morphology analysis, EDS energy spectrum analysis, and metallographic analysis are adopted to analyze the causes of water seepage, the improvement measures are proposed. The results show that the presence of nodular slag defects inside the cylinder cover is the main cause of water seepage in the marine engine cylinder cover. Under the cyclic operating conditions of the engine bench test,some dense nodular slag defects form channels penetrating the cylinder head wall. By improving the casting process of the cylinder cover and adding air tightness test in the finished product inspection process, the risk of water seepage in the cylinder cover can be effectively prevented.

Keywords: cylinder cover; nodular slag; physical and chemical inspection; mechanical property analysis