去掉氧化皮，装配过程中零件表面涂上油，以防锈蚀。

Remove scale, in the process of assembly parts surface oil, in case of rust.

youdao

去掉氧化皮，装配过程中零件表面涂上油，以防锈蚀。

Remove scale, in the process of assembly parts surface oil, in case of rust.

youdao