DEVELOPMENT OF AND RESEARCH INTO CONTINUOUS EXTRUSION

摘要

The development of a continuous process - with no spare time in the cycle - would represent a further development of metal extrusion. It will also increase productivity and provide a stationary aspect to the metal flow, no matter what amount of billets are being continuously extruded. The first experimental models of hydraulic presses for continuous extrusion appeared abroad at the start of the 1960s in the electrical engineering industry. However, the extrusion flowsheets which were proposed then used large size billets which required high power consumption under continuous process conditions. In addition, production was lower than when the extrusion was interrupted. Thus, the only hydraulic press being introduced today for continuous pressing - by the Hydraulic Co (FRG) (30 MN force, for billets 175 X 620 mm in diameter) - has a productivity <0.8 tons/hr, compared to the productivity of conventional presses operating today on continuous extrusion, i.e., 1.0-1.2 tons/hr. Moreover, the pressing pressure for even pure aluminum attains levels which are practically the maximum for steel from which containers are manufactured (1000-1200 MPa, according to VNIIKP data).