东风1、2、3型内燃机车是目前我国铁路运输中使用较多的机车,其动力装置为L207E系列柴油机。该系列柴油机的活塞环材料为合金铸铁。由于材料和结构上的原因,活塞环存在铜衬(压力环为镶铜衬结构)脱落、环体折断、弹力消失、不耐磨等问题,使用寿命很短(机车走行7～9万公里后,进行大轮修时几乎全部需要更换),从而显著地增加了柴油机的检修工作重。为了解决这一问题,对L207E系列柴油机活塞环的材料和结构进行了试验研究。全部试验包括蠕虫状石墨铸铁的选材, Dongfeng 1,2,3 diesel locomotive is currently used in China’s railway transport more locomotives, the power plant for the L207E series diesel engine. The series of diesel piston ring material for the alloy cast iron. Due to material and structural reasons, the piston ring has copper lining (pressure ring is lined with copper lining structure), the ring body is broken, the elastic force disappears, and the wear resistance and other problems are short, and the service life is very short (70,000 to 90,000 km , Almost all need to be replaced when the big round of repair), which significantly increased the maintenance workload of diesel engines. In order to solve this problem, the material and structure of L207E series diesel piston rings were studied. All tests include the selection of vermicular graphite cast iron,