A.手工定時(shí)潤滑 B.壓力供油潤滑 C.濺油潤滑 D.油霧潤滑
A.0.6% B.2.11% C.10% D.12%
A.是低合金鋼 B.平均含碳量為40% C.Cr含量小于0.1% D.是碳鋼