concentricity(A derivation of the Mannesmann tube-process has been developed, using a piercer with three rolls, which has greater accuracy and concentricity. 曼内斯曼制管法的进一步发展,开始使用三辊穿孔机,它具有更高的加工精度和同心度。)
synchronous oscillation of mold(【技】结晶器最早采用的一种振动模式,即结晶器下降时与铸坯同步,然后以三倍的拉速上升,如此往复振动。结晶器这种振动模式的优点是能够满足连铸工艺要求,实现同步运动;缺点是用机械联锁或用电气控制来实现严格的同步要求,装置比较复杂,速度变化时机构的冲击力较大。)