浙江至德鋼業有限公司技術人員用壓力將經過加熱的不銹鋼彎頭推向一個后端加以固定的頂桿，該頂桿的頂頭位于由一對軋輥組成的圓孔型的中心，因此軸向的推力和徑向的軋制力同時作用在方坯上，使彎頭經過頂頭和圓孔型穿孔成為空心坯。在變形過程中只出現壓應力、基本上消除了拉伸應力、剪切應力和連續滑動現象，故穿孔后的不銹鋼彎頭的金屬組織大大改善。

  如圖17-1所(suo)示，經過(guo)加熱(re)(re)的(de)(de)(de)(de)(de)不銹(xiu)鋼彎頭BL經消除氧化(hua)鐵(tie)皮和(he)定型(xing)后(hou)(hou)，被送(song)至(zhi)壓(ya)力(li)穿(chuan)孔(kong)(kong)(kong)(kong)(kong)(kong)機(ji)(ji)(ji)的(de)(de)(de)(de)(de)受料槽(cao)內(nei)，并(bing)處于(yu)液壓(ya)推(tui)鋼機(ji)(ji)(ji)AP和(he)軋(ya)(ya)機(ji)(ji)(ji)機(ji)(ji)(ji)架間(jian)。液力(li)推(tui)鋼機(ji)(ji)(ji)AP將經過(guo)熱(re)(re)定心的(de)(de)(de)(de)(de)方坯(pi)(pi)(pi)推(tui)入(ru)一個堅(jian)固(gu)的(de)(de)(de)(de)(de)、公差(cha)很(hen)(hen)小(xiao)的(de)(de)(de)(de)(de)方形入(ru)口導(dao)套IG,使方坯(pi)(pi)(pi)同(tong)時(shi)和(he)穿(chuan)孔(kong)(kong)(kong)(kong)(kong)(kong)機(ji)(ji)(ji)頭PP和(he)軋(ya)(ya)輥RG相(xiang)遇，并(bing)在整(zheng)個穿(chuan)孔(kong)(kong)(kong)(kong)(kong)(kong)過(guo)程維(wei)持(chi)恒定的(de)(de)(de)(de)(de)推(tui)力(li)，然后(hou)(hou)即(ji)作用在它圓形的(de)(de)(de)(de)(de)外(wai)表面上(shang)，當空心坯(pi)(pi)(pi)HB由軋(ya)(ya)輥孔(kong)(kong)(kong)(kong)(kong)(kong)型(xing)中軋(ya)(ya)出時(shi)，立(li)即(ji)進入(ru)堅(jian)固(gu)的(de)(de)(de)(de)(de)配合得很(hen)(hen)緊密(mi)的(de)(de)(de)(de)(de)出口中導(dao)套OG.導(dao)環(huan)CG,在穿(chuan)孔(kong)(kong)(kong)(kong)(kong)(kong)開(kai)始(shi)時(shi)位于(yu)頂(ding)(ding)桿(gan)PB的(de)(de)(de)(de)(de)前(qian)(qian)(qian)端，而當空心坯(pi)(pi)(pi)進入(ru)出口導(dao)套0G時(shi)，它與導(dao)環(huan)CG相(xiang)遇，并(bing)推(tui)動(dong)導(dao)環(huan)CG前(qian)(qian)(qian)進而空心坯(pi)(pi)(pi)本身(shen)逐漸(jian)起到(dao)定心的(de)(de)(de)(de)(de)作用。因(yin)此(ci)只要正確地調(diao)整(zheng)入(ru)口導(dao)套IG,軋(ya)(ya)輥RG和(he)出口導(dao)套OG即(ji)可(ke)保(bao)證不銹(xiu)鋼彎頭、頂(ding)(ding)頭與頂(ding)(ding)桿(gan)三者(zhe)的(de)(de)(de)(de)(de)中心線(xian)在同(tong)一直線(xian)上(shang)，故壓(ya)力(li)穿(chuan)孔(kong)(kong)(kong)(kong)(kong)(kong)后(hou)(hou)，空心坯(pi)(pi)(pi)壁厚比較(jiao)均勻。當穿(chuan)孔(kong)(kong)(kong)(kong)(kong)(kong)操作將要結束時(shi)，液力(li)推(tui)鋼機(ji)(ji)(ji)的(de)(de)(de)(de)(de)柱塞桿(gan)IP自動(dong)停止前(qian)(qian)(qian)進，而推(tui)鋼機(ji)(ji)(ji)外(wai)環(huan)繼續前(qian)(qian)(qian)進，直至(zhi)與頂(ding)(ding)頭相(xiang)遇為止，此(ci)時(shi)不銹(xiu)鋼彎頭后(hou)(hou)部的(de)(de)(de)(de)(de)穿(chuan)孔(kong)(kong)(kong)(kong)(kong)(kong)全靠徑向(xiang)軋(ya)(ya)制力(li)來完(wan)成。方坯(pi)(pi)(pi)穿(chuan)孔(kong)(kong)(kong)(kong)(kong)(kong)后(hou)(hou)，打(da)開(kai)鎖門(men)，水冷頂(ding)(ding)桿(gan)由空心坯(pi)(pi)(pi)內(nei)抽出，其動(dong)作和(he)斜軋(ya)(ya)穿(chuan)孔(kong)(kong)(kong)(kong)(kong)(kong)機(ji)(ji)(ji)是相(xiang)同(tong)的(de)(de)(de)(de)(de)。