摘要:某船舶柴油机排气阀-阀座密封锥面应用同种堆焊材料,经长时间运行磨损轻微,并未发现明显的黏着磨损痕迹。通过观察磨损表面形貌、分析微区成分,探讨该排气阀-阀座匹配方案的磨损机理。研究表明:燃烧废气在排气阀密封锥面形成一层沉积膜,通过隔离密封面及固体润滑的方式降低摩擦副发生黏着磨损的倾向;在落座及燃烧压力的交变应力下,排气阀锥面堆焊层的磨损机理主要为疲劳剥落,而排气阀座锥面堆焊层的磨损机理为抛光产生的缓慢磨粒磨损。 |
关键词: 排气阀 排气阀座 磨损机理 |
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Wear Mechanism of the Weld Deposit Layer on the Conical Surface of Exhaust Valve and Valve Seat |
ZHU Feng,LI Liting,TANG Yihu,ZHANG Guoyong |
Shanghai Marine Diesel Engine Research Institute,Shanghai 201108,China |
Abstract:Exhaust valve and valve seat with same weld deposit materials were used in a marine diesel engine.After a long period of operation,the exhaust valve and seat ring wore slightly,no obvious adhesive wear was found. By observing the morphology of the worn surface and analyzing the composition of the micro-area,the wear mechanism of the exhaust valve and valve seat matching scheme was explored.Research shows that:Combustion exhaust gas forms a deposition film on the sealing conical surface of the exhaust valve,which reduces the tendency of friction pairs to experience adhesive wear by isolating the sealing surface and solid lubrication;Under the alternating stress of seating and combustion pressure,the wear mechanism of the weld deposit layer on the conical surface of the exhaust valve is mainly fatigue peeling,while the wear mechanism of the weld deposit layer on the conical surface of the exhaust valve seat is slow abrasion caused by polishing. |
Key words: exhaust valve exhaust valve seat wear mechanism |