1. 桶形輥(gun)穿(chuan)孔機
桶形二輥(gun)穿(chuan)孔(kong)(kong)機是(shi)根據孔(kong)(kong)腔形成原理，利用旋轉(zhuan)(zhuan)橫鍛(duan)效(xiao)應穿(chuan)孔(kong)(kong)。正是(shi)這(zhe)種孔(kong)(kong)腔現(xian)象造成了鋼管內表(biao)面(mian)的(de)(de)缺(que)陷，旋轉(zhuan)(zhuan)橫鍛(duan)效(xiao)應又使毛管有較大的(de)(de)周向切應力(li)和表(biao)面(mian)扭(niu)轉(zhuan)(zhuan)變形，因此，桶式穿(chuan)孔(kong)(kong)機很難滿足穿(chuan)軋(ya)高合金鋼的(de)(de)要求。
2. 錐(zhui)形輥穿孔機
錐形(xing)(xing)輥(gun)(gun)穿(chuan)(chuan)孔(kong)機(ji)(ji)(ji)采(cai)用(yong)較(jiao)大(da)的(de)(de)輾(zhan)軋(ya)(ya)角(jiao)(jiao)(jiao)和(he)(he)送(song)進(jin)(jin)角(jiao)(jiao)(jiao)進(jin)(jin)行斜軋(ya)(ya)穿(chuan)(chuan)孔(kong)，同(tong)時(shi)又極力控制旋轉(zhuan)橫鍛效應的(de)(de)產生(sheng)及控制毛管(guan)的(de)(de)周(zhou)向(xiang)切應力與表面扭轉(zhuan)變(bian)形(xing)(xing)。因此，錐形(xing)(xing)輥(gun)(gun)穿(chuan)(chuan)孔(kong)機(ji)(ji)(ji)可以實(shi)現與擠壓機(ji)(ji)(ji)相近的(de)(de)金(jin)屬流動。從工(gong)藝參數方面講(jiang)，錐形(xing)(xing)輥(gun)(gun)穿(chuan)(chuan)孔(kong)機(ji)(ji)(ji)基本(ben)要點(dian)是(shi)兩個角(jiao)(jiao)(jiao)度(du)值的(de)(de)問題即輾(zhan)軋(ya)(ya)角(jiao)(jiao)(jiao)和(he)(he)送(song)進(jin)(jin)角(jiao)(jiao)(jiao)。前(qian)者對一個機(ji)(ji)(ji)組來講(jiang)是(shi)定(ding)值，后者根據(ju)設計可調整，若錐形(xing)(xing)輥(gun)(gun)穿(chuan)(chuan)孔(kong)機(ji)(ji)(ji)采(cai)取軋(ya)(ya)輥(gun)(gun)水平布(bu)置方式(shi)，故可采(cai)用(yong)更大(da)的(de)(de)輾(zhan)軋(ya)(ya)角(jiao)(jiao)(jiao)β（27.6°）和(he)(he)相對較(jiao)小的(de)(de)送(song)進(jin)(jin)角(jiao)(jiao)(jiao)α(6°~12°)，若這種(zhong)軋(ya)(ya)機(ji)(ji)(ji)發(fa)(fa)(fa)展為軋(ya)(ya)輥(gun)(gun)上(shang)下(xia)布(bu)置時(shi)，這樣大(da)的(de)(de)輾(zhan)軋(ya)(ya)角(jiao)(jiao)(jiao)顯(xian)然不行，而且從工(gong)藝上(shang)講(jiang)，一般(ban)以β+α=25°~30°作為一判(pan)定(ding)值，故曼內(nei)斯(si)曼鋼管(guan)公司在(zai)后來的(de)(de)設計中(zhong)(zhong)，隨著軋(ya)(ya)輥(gun)(gun)上(shang)下(xia)布(bu)置形(xing)(xing)式(shi)的(de)(de)進(jin)(jin)一步(bu)發(fa)(fa)(fa)展，將β角(jiao)(jiao)(jiao)降為10°~15°。輾(zhan)軋(ya)(ya)角(jiao)(jiao)(jiao)和(he)(he)可調的(de)(de)送(song)進(jin)(jin)角(jiao)(jiao)(jiao)的(de)(de)各種(zhong)配合(he)，對穿(chuan)(chuan)孔(kong)過(guo)程中(zhong)(zhong)所發(fa)(fa)(fa)生(sheng)的(de)(de)切向(xiang)變(bian)形(xing)(xing)確實(shi)產生(sheng)相當大(da)的(de)(de)影響。
