美國Phoenix 鋼鐵公司無縫鋼管廠采用Calmes軋管工藝,其軋管機組的平面布置圖是由意大利 Albert Calmes博士設計的,Phoenix 鋼鐵公司設計科在其他工程公司的配合下完成詳細設計,為了生產各種鋼號的優質無縫鋼管,使其內外徑和壁厚均具有良好的公差,軋管機組的設計以下列三方面內容為核心:Calmes在水壓沖孔機方面的專利、Calmes關于改進曼內斯曼延伸機方面的專利以及他所提出的周期軋管機的軋輥孔型。
這一(yi)軋管(guan)機組采用Phoenix 鋼(gang)鐵(tie)公司平爐頂鑄生產的最大重量達8000磅(bang)的波浪形鋼(gang)錠為原料,成品管(guan)直徑為51/2~16英(ying)寸(cun)壁(bi)厚為1/4~3英(ying)寸(cun)。
這種(zhong)軋管(guan)機(ji)組的(de)一(yi)大(da)特點(dian)是(shi)直接(jie)采(cai)用(yong)平爐鋼(gang)錠在一(yi)個連續的(de)工藝(yi)過(guo)程(cheng)中軋制(zhi)成(cheng)管(guan),并且僅(jin)一(yi)次加熱(re)就能完成(cheng)沖孔、延(yan)伸,周(zhou)期軋管(guan)各工藝(yi)過(guo)程(cheng),其(qi)主要(yao)工藝(yi)過(guo)程(cheng)是(shi):鋼(gang)錠清理、加熱(re)、沖孔、延(yan)伸、周(zhou)期軋管(guan),再(zai)加熱(re)、定徑、修磨,精整和水壓試(shi)驗,以下主要(yao)論述沖孔、延(yan)伸和周(zhou)期軋管(guan)等三個工藝(yi)過(guo)程(cheng)。
1. 水壓沖孔
鋼(gang)錠(ding)(ding)(ding)經火焰燒剝去除表面缺陷后,在(zai)車(che)底式加熱爐內加熱到(dao)(dao)2340~2370℉。用(yong)小車(che)運送(song)到(dao)(dao)沖(chong)(chong)(chong)孔(kong)(kong)(kong)(kong)(kong)(kong)機(ji)上(shang)(shang)進行沖(chong)(chong)(chong)孔(kong)(kong)(kong)(kong)(kong)(kong)操(cao)(cao)作。鋼(gang)錠(ding)(ding)(ding)在(zai)1200t水(shui)壓(ya)沖(chong)(chong)(chong)孔(kong)(kong)(kong)(kong)(kong)(kong)機(ji)上(shang)(shang)沖(chong)(chong)(chong)孔(kong)(kong)(kong)(kong)(kong)(kong),其操(cao)(cao)作過程如下(xia):用(yong)水(shui)壓(ya)操(cao)(cao)縱的(de)(de)裝(zhuang)料機(ji)將(jiang)鋼(gang)錠(ding)(ding)(ding)送(song)人沖(chong)(chong)(chong)孔(kong)(kong)(kong)(kong)(kong)(kong)機(ji),將(jiang)其置(zhi)于支(zhi)(zhi)架上(shang)(shang)的(de)(de)沖(chong)(chong)(chong)孔(kong)(kong)(kong)(kong)(kong)(kong)位置(zhi),兩個(ge)支(zhi)(zhi)架中有一個(ge)是固定(ding)在(zai)沖(chong)(chong)(chong)孔(kong)(kong)(kong)(kong)(kong)(kong)模(mo)上(shang)(shang)的(de)(de),而另(ling)一個(ge)則可(ke)以伸縮,沖(chong)(chong)(chong)孔(kong)(kong)(kong)(kong)(kong)(kong)模(mo)前(qian)移(yi)(yi)時即(ji)將(jiang)鋼(gang)錠(ding)(ding)(ding)套住,開始沖(chong)(chong)(chong)孔(kong)(kong)(kong)(kong)(kong)(kong)操(cao)(cao)作。鋼(gang)錠(ding)(ding)(ding)沖(chong)(chong)(chong)孔(kong)(kong)(kong)(kong)(kong)(kong)后,其形狀像杯(bei)子(zi),被(bei)稱為杯(bei)狀體,沖(chong)(chong)(chong)孔(kong)(kong)(kong)(kong)(kong)(kong)模(mo)的(de)(de)內徑決定(ding)杯(bei)狀體的(de)(de)外徑。沖(chong)(chong)(chong)頭(tou)直(zhi)徑則確(que)定(ding)杯(bei)狀體內孔(kong)(kong)(kong)(kong)(kong)(kong)的(de)(de)直(zhi)徑,圖(tu)13-1所示是沖(chong)(chong)(chong)孔(kong)(kong)(kong)(kong)(kong)(kong)模(mo)前(qian)移(yi)(yi)但尚未套上(shang)(shang)鋼(gang)錠(ding)(ding)(ding)前(qian)端時的(de)(de)狀況,沖(chong)(chong)(chong)孔(kong)(kong)(kong)(kong)(kong)(kong)模(mo)前(qian)移(yi)(yi)達到(dao)(dao)其沖(chong)(chong)(chong)程的(de)(de)75%,可(ke)伸縮支(zhi)(zhi)架從下(xia)部移(yi)(yi)出,圖(tu)13-2示出鋼(gang)錠(ding)(ding)(ding)已(yi)被(bei)套入沖(chong)(chong)(chong)孔(kong)(kong)(kong)(kong)(kong)(kong)模(mo)內。
圖13-3示出整(zheng)個(ge)杯狀(zhuang)體還套在(zai)沖(chong)孔(kong)模(mo)內的(de)情況(kuang),從(cong)圖13-3可以看出被沖(chong)孔(kong)的(de)鋼(gang)錠(ding)前端只(zhi)剩下很薄的(de)杯底(di)。鋼(gang)錠(ding)呈方形或圓形,即直徑(jing)為(wei)13英(ying)寸(cun)(cun),16英(ying)寸(cun)(cun),19英(ying)寸(cun)(cun)和21英(ying)寸(cun)(cun)的(de)波浪形圓錠(ding)。
2. 杯(bei)狀體(ti)延(yan)伸
在(zai)延(yan)伸機上(shang),杯狀體(ti)在(zai)兩(liang)個在(zai)水平面(mian)上(shang)成反向傾斜(xie)的(de)斜(xie)置軋輥間(jian),通過(guo)具有一(yi)定形(xing)(xing)狀的(de)頂頭進(jin)行軋制。在(zai)垂直平面(mian)上(shang)有兩(liang)個固定導板,其作用是限制變(bian)形(xing)(xing)區的(de)杯狀體(ti)的(de)斷面(mian)形(xing)(xing)狀使之(zhi)不至于過(guo)分橢圓。這種延(yan)伸機與(yu)曼(man)內(nei)斯曼(man)斜(xie)軋穿孔機很相(xiang)似,它可(ke)以(yi)延(yan)伸杯狀體(ti),并穿透(tou)杯底使之(zhi)成為空心坯。
圖13-4示(shi)出采用(yong)(yong)曼內斯曼輥(gun)型的延伸(shen)機(ji)對杯狀體進(jin)行(xing)延伸(shen)的過(guo)程。圖13-5所示(shi)是采用(yong)(yong)了Calmes軋(ya)輥(gun)的情(qing)況,空心坯延伸(shen)時,最好選用(yong)(yong)延伸(shen)率(lv) λ=1.75,最大不超過(guo)2。
延伸(shen)機采用3相、60Hz、功率為2208kW(3000馬力)的同步電(dian)機傳(chuan)動,額定電(dian)壓、轉速分別為6900V,1500r/min,減速機的速比為3。
延伸(shen)機的(de)主要特點之一是(shi)它所生(sheng)產的(de)空心坯壁(bi)厚比較均(jun)勻。斜軋延伸(shen)機的(de)延伸(shen)過程(cheng)可參(can)看圖13-6。
杯狀體離開(kai)(kai)軋輥成為空(kong)心坯后,用(yong)以夾(jia)持(chi)頂桿的(de)鎖門就打(da)開(kai)(kai),空(kong)心坯從延伸機(ji)(ji)輸出,用(yong)橫移(yi)小車將其(qi)運送到(dao)周期軋管機(ji)(ji)。
3. 周期(qi)軋(ya)管機軋(ya)管
周期軋管(guan)機(ji)由一(yi)(yi)臺額(e)定功率(lv)為(wei)1472kW(2000馬力(li))的電動(dong)(dong)機(ji)傳動(dong)(dong),該電動(dong)(dong)機(ji)的功率(lv)能達2208kW(3000馬力(li))而(er)不至(zhi)于過分(fen)發熱。電動(dong)(dong)機(ji)軸上配有飛輪,在每一(yi)(yi)轉中它既提(ti)供(gong)能量(liang)又獲得能量(liang),軋機(ji)速(su)(su)度(du)(du)是30~105r/min,較低的速(su)(su)度(du)(du)用(yong)于軋制(zhi)大管(guan),而(er)較高(gao)(gao)的速(su)(su)度(du)(du)用(yong)來軋小管(guan)。操作(zuo)(zuo)喂(wei)料器的高(gao)(gao)壓(ya)(ya)(ya)水(shui)壓(ya)(ya)(ya)力(li)為(wei)2800 Ibl/in或1500 Ibf/in,以向(xiang)一(yi)(yi)個前(qian)進缸(gang)和兩(liang)個回程(cheng)缸(gang)供(gong)水(shui),正(zheng)常(chang)運轉時(shi)(shi)(shi),向(xiang)前(qian)進缸(gang)連續(xu)地(di)供(gong)高(gao)(gao)壓(ya)(ya)(ya)水(shui),向(xiang)前(qian)喂(wei)料時(shi)(shi)(shi),高(gao)(gao)壓(ya)(ya)(ya)水(shui)由回程(cheng)缸(gang)流出,因此向(xiang)前(qian)喂(wei)料的速(su)(su)度(du)(du)受(shou)到從回程(cheng)缸(gang)排出的高(gao)(gao)壓(ya)(ya)(ya)水(shui)量(liang)的控(kong)(kong)制(zhi)。這(zhe)一(yi)(yi)操作(zuo)(zuo)在咬人時(shi)(shi)(shi)是手工操作(zuo)(zuo),由操作(zuo)(zuo)工自(zi)行控(kong)(kong)制(zhi),軋制(zhi)時(shi)(shi)(shi)則是自(zi)動(dong)(dong)操作(zuo)(zuo)的,操作(zuo)(zuo)工應(ying)使喂(wei)料器的前(qian)進速(su)(su)度(du)(du)與軋輥的速(su)(su)度(du)(du)同步;此外,操作(zuo)(zuo)工還必須控(kong)(kong)制(zhi)空氣壓(ya)(ya)(ya)力(li)p1,空心坯咬人時(shi)(shi)(shi),迅(xun)速(su)(su)把空氣從缸(gang)里排出,開始軋制(zhi)后,根據所軋管(guan)子(zi)的規格調整(zheng)空氣壓(ya)(ya)(ya)力(li)P1.液(ye)壓(ya)(ya)(ya)自(zi)動(dong)(dong)喂(wei)料器斷(duan)面(mian)示意圖如圖13-7所示。
該喂料(liao)器的(de)(de)(de)(de)一(yi)(yi)個特點是,空氣(qi)缸的(de)(de)(de)(de)沖程(cheng)長度(du)(du)(du)都(dou)保持(chi)不變(bian)。軋制(zhi)152~203mm管子時(shi)沖程(cheng)長度(du)(du)(du)為(wei)(wei)(wei)762mm,而軋制(zhi)228~406mm的(de)(de)(de)(de)管子時(shi),則沖程(cheng)長度(du)(du)(du)為(wei)(wei)(wei)838mm.這意味著(zhu)軋輥工作(zuo)段(duan)長度(du)(du)(du)是恒定不變(bian)的(de)(de)(de)(de),在軋輥車床(chuang)上凸輪的(de)(de)(de)(de)安裝位置(zhi)恰(qia)可使軋輥的(de)(de)(de)(de)工作(zuo)段(duan)和(he)所對應的(de)(de)(de)(de)喂料(liao)器一(yi)(yi)致。喂料(liao)的(de)(de)(de)(de)方向與(yu)軋輥旋(xuan)轉(zhuan)的(de)(de)(de)(de)方向是相反的(de)(de)(de)(de),軋機操作(zuo)工控(kong)制(zhi)喂料(liao)速(su)度(du)(du)(du)并將此速(su)度(du)(du)(du)和(he)軋輥轉(zhuan)速(su)保持(chi)同(tong)步。芯(xin)棒長度(du)(du)(du)為(wei)(wei)(wei)4572~4877mm,同(tong)時(shi)使用的(de)(de)(de)(de)芯(xin)棒為(wei)(wei)(wei)5根(gen),其中(zhong)一(yi)(yi)根(gen)芯(xin)棒用于軋制(zhi),其余芯(xin)棒在空氣(qi)中(zhong)冷卻(que),然后浸人水中(zhong)進(jin)一(yi)(yi)步冷卻(que),一(yi)(yi)般(ban)是3根(gen)芯(xin)棒在空氣(qi)中(zhong)冷卻(que),一(yi)(yi)根(gen)芯(xin)棒在水里冷卻(que),軋機運(yun)行中(zhong)5根(gen)芯(xin)棒就這樣反復(fu)循環著(zhu)。
根據(ju)所軋(ya)(ya)管子規(gui)格調(diao)(diao)下(xia)(xia)輥高(gao)(gao)度,調(diao)(diao)整后(hou)其高(gao)(gao)度是(shi)(shi)不變的(de)。當(dang)空心坯(pi)被軋(ya)(ya)成帶有皮爾格頭的(de)管子后(hou),應將上輥抬起。上輥是(shi)(shi)由(you)高(gao)(gao)壓水缸來(lai)平衡(heng)的(de),其升(sheng)降由(you)電動(dong)(dong)機操(cao)作,由(you)于(yu)芯棒(bang)全長有1.6mm左右的(de)“退拔”,為使壁厚保持不變,軋(ya)(ya)制時通過一個微(wei)調(diao)(diao)裝(zhuang)置(zhi)而將軋(ya)(ya)輥升(sheng)高(gao)(gao),微(wei)調(diao)(diao)裝(zhuang)置(zhi)由(you)專用電動(dong)(dong)機和減(jian)速箱(xiang)組成,減(jian)速箱(xiang)的(de)出軸通過空氣離合器與壓下(xia)(xia)螺絲(si)電動(dong)(dong)機的(de)軸相連,軋(ya)(ya)制時操(cao)作工將上軋(ya)(ya)輥逐漸抬高(gao)(gao)以補償芯棒(bang)的(de)錐度和熱膨脹。
軋(ya)制過程中金屬(shu)流動(dong)(dong)的方向(xiang)與喂料(liao)的方向(xiang)相同,軋(ya)輥(gun)(gun)每轉一周后,芯(xin)棒回轉90°左(zuo)右(you)。當(dang)空心(xin)坯被軋(ya)制并由芯(xin)棒前端(duan)向(xiang)前移動(dong)(dong)時,毛管繼續在(zai)導槽上(shang)滑移,空心(xin)坯完全軋(ya)成管子后,上(shang)軋(ya)輥(gun)(gun)抬(tai)起,升(sheng)降輥(gun)(gun)升(sheng)起,將毛管輸送到(dao)熱鋸,切去端(duan)頭(tou)和皮爾格頭(tou),然后測量(liang)(liang)和稱量(liang)(liang)管子,在(zai)管壁上(shang)標出測得的重量(liang)(liang)。