國外穿孔機的發展概況
1.二輥(gun)穿(chuan)(chuan)孔(kong)機的發展 熱軋無縫鋼管生產中(zhong)(zhong)管坯的穿(chuan)(chuan)孔(kong)主要是在(zai)斜軋穿(chuan)(chuan)孔(kong)機上進行的,直至1970年(nian),在(zai)斜軋穿(chuan)(chuan)孔(kong)機中(zhong)(zhong)設(she)有導(dao)板的Stiefel穿(chuan)(chuan)孔(kong)機最為普遍(bian),見圖6-31所示。它(ta)也被(bei)稱作具有桶形軋輥(gun)的穿(chuan)(chuan)孔(kong)機。由于(yu)它(ta)的性能好,延伸率可達4、穿(chuan)(chuan)孔(kong)后空心坯長度可長達8m,所以,它(ta)被(bei)...