A.臺(tái)金滲透鋼20CrMnMoA B.鑄鋼 C.優(yōu)質(zhì)合金鋼 D.鑄鐵
A.128mm B.139mm C.146mm D.150mm
A.轉(zhuǎn)向架兩端輪對(duì)軸箱上 B.中間輪對(duì)軸箱上 C.機(jī)車中間輪對(duì)軸箱上 D.不一定