(一)概述发动机的大修寿命,在很大程度上由气缸套的损伤(内表面磨损和外壁穴蚀)决定。近年来,随着对发动机的不断强化,气缸套的工作条件(即热负荷与机械负荷)更加苛刻,损伤也更严重,它的使用寿命已成为使用部门很为关切的问题。国内机车上使用的二冲程柴汕机缸套,由于严重的段磨现象,寿命只有10～20万公里,机车在架修中,甚至有50％的缸套被更换。机 (A) Overview Engine overhaul life, to a large extent by the cylinder liner damage (wear on the inner surface and wall cavitation) decision. In recent years, with the continuous enhancement of the engine, the working conditions of the cylinder liner (ie, thermal load and mechanical load) are more severe and the damage is more serious. Its service life has become a concern for the user department. Two-stroke diesel locomotive cylinder liner used on domestic locomotives has a life span of only 10 to 200,000 km due to severe segment grinding. Locomotives are even under construction with 50% of the liner replaced. machine