A.Q235 B.16MR C.25CrMo D.1Cr18Ni9Ti
A.輸送介質(zhì)的壓力、溫度、化學(xué)性質(zhì) B.外部環(huán)境 C.大氣狀況 D.介質(zhì)溫度
A.前1/2 B.1/2~2/3 C.1/3~2/3 D.1/2~1~3