浙江至德鋼業有限公司為了減少不(bu)銹(xiu)鋼管(guan)坯(pi)料與工模具接觸表面的溫降，有利于玻璃潤滑劑的軟化，提高潤滑效果，降低工模具表面熱沖擊引起的溫度應力，提高工模具的使用壽命，擠壓工模具使用前應進行預熱，其預熱溫度與擠壓材料和工模具的材質有關。擠壓不銹鋼管和型材時，工模具的預熱溫度見表2-25。

 美國PMAC公司的(de)2500噸擠(ji)(ji)壓(ya)(ya)(ya)(ya)機推薦的(de)預(yu)熱(re)(re)(re)溫(wen)度如下(xia)：工具鋼制作的(de)擠(ji)(ji)壓(ya)(ya)(ya)(ya)模和(he)穿(chuan)孔(kong)頭為(wei)200℃，擠(ji)(ji)壓(ya)(ya)(ya)(ya)芯棒為(wei)250~320℃，擠(ji)(ji)壓(ya)(ya)(ya)(ya)筒(tong)為(wei)260~320℃，穿(chuan)孔(kong)筒(tong)為(wei)360~370℃。擠(ji)(ji)壓(ya)(ya)(ya)(ya)模、擠(ji)(ji)壓(ya)(ya)(ya)(ya)墊(dian)、芯棒等(deng)小型(xing)工模具的(de)預(yu)熱(re)(re)(re)一般采(cai)用箱式電(dian)爐。擠(ji)(ji)壓(ya)(ya)(ya)(ya)筒(tong)的(de)預(yu)熱(re)(re)(re)主要(yao)有電(dian)阻加(jia)熱(re)(re)(re)和(he)感應加(jia)熱(re)(re)(re)兩種。感應加(jia)熱(re)(re)(re)是將感應線圈(quan)放入擠(ji)(ji)壓(ya)(ya)(ya)(ya)筒(tong)內進行加(jia)熱(re)(re)(re)，加(jia)熱(re)(re)(re)時(shi)(shi)熱(re)(re)(re)流由內襯向外傳導(dao)，擠(ji)(ji)壓(ya)(ya)(ya)(ya)簡(jian)內的(de)溫(wen)度分布較電(dian)阻加(jia)熱(re)(re)(re)合理（圖2-41),因(yin)為(wei)內襯、中(zhong)和(he)外套之間的(de)過(guo)盈配合應力不(bu)會降低，但(dan)感應加(jia)熱(re)(re)(re)時(shi)(shi)操(cao)作不(bu)便，感應圈(quan)易損壞，所以目(mu)前主要(yao)還是采(cai)用電(dian)阻加(jia)熱(re)(re)(re)。

 在(zai)(zai)正常擠(ji)壓(ya)(ya)(ya)(ya)生產不銹鋼管過(guo)程(cheng)中(zhong)，擠(ji)壓(ya)(ya)(ya)(ya)工(gong)(gong)模(mo)(mo)(mo)具(ju)連(lian)續使(shi)(shi)(shi)用(yong)(yong)(yong)時(shi)，溫(wen)度(du)(du)將會逐(zhu)漸升高(gao)，而引起工(gong)(gong)模(mo)(mo)(mo)具(ju)材質高(gao)溫(wen)回火(huo)，降低(di)了紅硬性，導致工(gong)(gong)模(mo)(mo)(mo)具(ju)產生變(bian)形而影(ying)響(xiang)擠(ji)壓(ya)(ya)(ya)(ya)過(guo)程(cheng)的(de)(de)(de)(de)順利進(jin)行。如(ru)擠(ji)壓(ya)(ya)(ya)(ya)墊的(de)(de)(de)(de)使(shi)(shi)(shi)用(yong)(yong)(yong)溫(wen)度(du)(du)過(guo)高(gao)，因熱膨脹過(guo)大(da)(da)產生變(bian)形而引起擠(ji)壓(ya)(ya)(ya)(ya)墊卡在(zai)(zai)擠(ji)壓(ya)(ya)(ya)(ya)筒內。為此，擠(ji)壓(ya)(ya)(ya)(ya)工(gong)(gong)模(mo)(mo)(mo)具(ju)在(zai)(zai)使(shi)(shi)(shi)用(yong)(yong)(yong)過(guo)程(cheng)中(zhong)又需要(yao)(yao)進(jin)行必要(yao)(yao)的(de)(de)(de)(de)冷(leng)(leng)(leng)(leng)(leng)(leng)卻(que)(que)，使(shi)(shi)(shi)其保持在(zai)(zai)所(suo)要(yao)(yao)求的(de)(de)(de)(de)溫(wen)度(du)(du)范圍(wei)內工(gong)(gong)作。對于外(wai)套(tao)內襯(chen)擠(ji)壓(ya)(ya)(ya)(ya)墊，擠(ji)壓(ya)(ya)(ya)(ya)模(mo)(mo)(mo)和(he)(he)小直徑的(de)(de)(de)(de)芯(xin)(xin)棒(bang)一(yi)般(ban)可以采用(yong)(yong)(yong)3~4個循環(huan)輪流使(shi)(shi)(shi)用(yong)(yong)(yong)，必要(yao)(yao)時(shi)也(ye)可以在(zai)(zai)擠(ji)壓(ya)(ya)(ya)(ya)結束后進(jin)行水(shui)(shui)冷(leng)(leng)(leng)(leng)(leng)(leng)或噴(pen)(pen)(pen)水(shui)(shui)冷(leng)(leng)(leng)(leng)(leng)(leng)卻(que)(que)。對于擠(ji)壓(ya)(ya)(ya)(ya)筒和(he)(he)大(da)(da)直徑的(de)(de)(de)(de)芯(xin)(xin)棒(bang)等大(da)(da)型工(gong)(gong)模(mo)(mo)(mo)具(ju)，在(zai)(zai)使(shi)(shi)(shi)用(yong)(yong)(yong)過(guo)程(cheng)中(zhong)吸(xi)熱量大(da)(da)，更換又不方便(bian)，故只(zhi)能采用(yong)(yong)(yong)專門的(de)(de)(de)(de)冷(leng)(leng)(leng)(leng)(leng)(leng)卻(que)(que)裝置(zhi)來進(jin)行冷(leng)(leng)(leng)(leng)(leng)(leng)卻(que)(que)。如(ru)擠(ji)壓(ya)(ya)(ya)(ya)筒的(de)(de)(de)(de)冷(leng)(leng)(leng)(leng)(leng)(leng)卻(que)(que)方式(shi)(shi)有內部通(tong)水(shui)(shui)冷(leng)(leng)(leng)(leng)(leng)(leng)卻(que)(que)（內冷(leng)(leng)(leng)(leng)(leng)(leng)式(shi)(shi)）和(he)(he)內襯(chen)噴(pen)(pen)(pen)水(shui)(shui)冷(leng)(leng)(leng)(leng)(leng)(leng)卻(que)(que)（外(wai)冷(leng)(leng)(leng)(leng)(leng)(leng)式(shi)(shi)）兩種(zhong)。內冷(leng)(leng)(leng)(leng)(leng)(leng)式(shi)(shi)（圖(tu)2-42)是在(zai)(zai)中(zhong)襯(chen)內孔表面(mian)加(jia)工(gong)(gong)有螺旋形冷(leng)(leng)(leng)(leng)(leng)(leng)卻(que)(que)槽，當(dang)擠(ji)壓(ya)(ya)(ya)(ya)筒溫(wen)度(du)(du)過(guo)高(gao)時(shi)，通(tong)入水(shui)(shui)溫(wen)不低(di)于60~65℃的(de)(de)(de)(de)冷(leng)(leng)(leng)(leng)(leng)(leng)卻(que)(que)水(shui)(shui)，以防止過(guo)冷(leng)(leng)(leng)(leng)(leng)(leng)引起裂紋，設有電加(jia)熱器(qi)與水(shui)(shui)冷(leng)(leng)(leng)(leng)(leng)(leng)卻(que)(que)裝置(zhi)的(de)(de)(de)(de)擠(ji)壓(ya)(ya)(ya)(ya)筒，如(ru)圖(tu)2-43所(suo)示(shi)；外(wai)冷(leng)(leng)(leng)(leng)(leng)(leng)式(shi)(shi)是當(dang)擠(ji)壓(ya)(ya)(ya)(ya)循環(huan)結束時(shi)，采用(yong)(yong)(yong)環(huan)狀噴(pen)(pen)(pen)嘴(zui)在(zai)(zai)擠(ji)壓(ya)(ya)(ya)(ya)筒一(yi)端(duan)向筒內噴(pen)(pen)(pen)入壓(ya)(ya)(ya)(ya)力水(shui)(shui)冷(leng)(leng)(leng)(leng)(leng)(leng)卻(que)(que)，這種(zhong)方法比較簡單(dan)，但內襯(chen)的(de)(de)(de)(de)材質要(yao)(yao)具(ju)有良(liang)好的(de)(de)(de)(de)耐急(ji)冷(leng)(leng)(leng)(leng)(leng)(leng)急(ji)熱性能。擠(ji)壓(ya)(ya)(ya)(ya)芯(xin)(xin)棒(bang)的(de)(de)(de)(de)冷(leng)(leng)(leng)(leng)(leng)(leng)卻(que)(que)也(ye)有內冷(leng)(leng)(leng)(leng)(leng)(leng)式(shi)(shi)和(he)(he)外(wai)冷(leng)(leng)(leng)(leng)(leng)(leng)式(shi)(shi)兩種(zhong)（圖(tu)2-44)。