當鋁單板軋(ya)件(jian)由(you)軋(ya)前的(de)(de)(de)原始(shi)厚度H經(jing)過軋(ya)制壓縮(suo)至軋(ya)后(hou)厚度h時人變(bian)(bian)形區的(de)(de)(de)軋(ya)件(jian)厚度逐(zhu)漸減薄，根據塑性變(bian)(bian)形的(de)(de)(de)體積不變(bian)(bian)條件(jian)，屬通過變(bian)(bian)形區內(nei)任(ren)意橫斷面的(de)(de)(de)秒流量必相(xiang)等。

    鋁(lv)單(dan)板軋(ya)(ya)制時軋(ya)(ya)件(jian)內金(jin)(jin)屬(shu)質點運(yun)動(dong)(dong)(dong)除(chu)塑性流動(dong)(dong)(dong)外(wai)，還受到旋轉(zhuan)軋(ya)(ya)輥的(de)機械運(yun)動(dong)(dong)(dong)的(de)影響，即鋁(lv)單(dan)板軋(ya)(ya)制時金(jin)(jin)屬(shu)質點的(de)流動(dong)(dong)(dong)速度是上述兩種運(yun)動(dong)(dong)(dong)速度的(de)合成。這是鋁(lv)單(dan)板軋(ya)(ya)制過程(cheng)金(jin)(jin)屬(shu)流動(dong)(dong)(dong)的(de)明顯特(te)點之一。

    平(ping)(ping)輥(gun)軋制時(shi)金(jin)(jin)屬(shu)質(zhi)點相對輥(gun)面(mian)(mian)的(de)流(liu)(liu)(liu)動(dong)(dong)(dong)與平(ping)(ping)錘壓縮，特別(bie)是楔形(xing)錘頭(tou)間(jian)壓縮時(shi)金(jin)(jin)屬(shu)的(de)流(liu)(liu)(liu)動(dong)(dong)(dong)十分相似(si)（圖3-6）。金(jin)(jin)屬(shu)塑性(xing)流(liu)(liu)(liu)動(dong)(dong)(dong)相對輥(gun)面(mian)(mian)的(de)滑動(dong)(dong)(dong)或滑動(dong)(dong)(dong)趨(qu)勢是：金(jin)(jin)屬(shu)向人(ren)口(kou)側(ce)（厚(hou)側(ce)AB邊）方(fang)向流(liu)(liu)(liu)動(dong)(dong)(dong)容(rong)易(yi)，而向出口(kou)側(ce)（薄側(ce)CD邊）流(liu)(liu)(liu)動(dong)(dong)(dong)較困難。金(jin)(jin)屬(shu)質(zhi)點向人(ren)口(kou)側(ce)流(liu)(liu)(liu)動(dong)(dong)(dong)形(xing)成(cheng)后(hou)滑區，而向出口(kou)側(ce)流(liu)(liu)(liu)動(dong)(dong)(dong)形(xing)成(cheng)前(qian)滑區。因(yin)而，軋制時(shi)的(de)流(liu)(liu)(liu)動(dong)(dong)(dong)分界面(mian)(mian)（中性(xing)面(mian)(mian)或中性(xing)線）偏向出口(kou)側(ce)。于是，按金(jin)(jin)屬(shu)塑性(xing)流(liu)(liu)(liu)動(dong)(dong)(dong)相對輥(gun)面(mian)(mian)的(de)運動(dong)(dong)(dong)情況，接觸(chu)弧面(mian)(mian)上(shang)有后(hou)滑區、中性(xing)面(mian)(mian)和前(qian)滑區。