重型LNG发动机气门及座圈磨损特性试验研究

Experimental Study on Wear Characteristics of Valve and Seat Ring of Heavy LNG Engine

本文基于发动机台架开展了重型LNG发动机气门及座圈磨损特性试验研究,并对磨损部件进行了磨损机理分析,研究结果表明:排气门及座圈的磨损程度远大于进气门及座圈。Crutonite镀铬排气门+J10排气门座圈组合的总磨损量远超标准限值,Crutonite氮化排气门+AP723排气门座圈组合的耐磨性较优,平均磨损量为0.057mm。21-4N氮化进气门+AP723进气门座圈组合以及21-4N氮化进气门+J160进气门座圈组合的磨损量均低于标准限值,相比较而言,前者的耐磨性能更优,平均磨损量为0.042mm。发动机进气门和排气门磨损部件主要是因为进排气门均存在实际工作温度过高现象,导致气门表面材料的显微组织发生分解或析出,从而出现麻点、麻坑、甚至烧蚀沟槽、弯曲变形。

Based on the engine bench,this paper carried out the experimental research on the wear characteristics of valve and seat ring of heavy LNG engine,and analyzed the wear mechanism of wear parts.The research results show that the wear degree of exhaust valve and seat ring is much greater than that of intake valve and seat ring.The total wear amount of Crutonite chrome plated exhaust valve+J10 exhaust valve seat combination far exceeds the standard limit.The wear resistance of Crutonite nitrided exhaust valve+AP723 exhaust valve seat combination is better,with an average wear amount of 0.057mm.The wear amount of 21-4N nitriding inlet valve+AP723 inlet valve seat assembly and 21-4N nitriding inlet valve+J160 inlet valve seat assembly are lower than the standard limit.In comparison,the wear resistance of the former is better,with an average wear amount of 0.042mm.The wear parts of engine inlet valve and exhaust valve are mainly due to the fact that the actual working temperature of inlet and exhaust valves is too high,which leads to the decomposition or precipitation of the microstructure of valve surface materials,resulting in pitting,pitting,even ablation groove,bending and deformation.