Method and appts. for prodn. of a semi-finished prod. - with smooth-rolling of the deposited metal ensures a small thickness tolerance

摘要

A cleaned metal profile with low heat content is continuously fed, from bottom to top, through a bath (1) of molten metal of the same kind. Dependent on the height of the bath, the speed of the profile is adjusted so that its thickness is increased at least three-fold through depositions on its surface. After leaving the bath in an inert atmos., the strip passes through smoothing rolls (4) - whose vertical position is adjustable - when the average temp. T of the added metal satisfies the relation T=T1+a(T2-T1), where T1 is the solidus temp., T2 is the liquidus temp. and a is a factor varying from 0.1-0.8. The factor a lies within the range of values from 0.2-0.4. The thickness reduction of the strip by smooth-rolling varies from 5-15% while the final-to-initial thickness ratio of the strip lies in the range 3-7. The vertical position of the smoothing rolls (4) is adjustable by electro-mechanical or hydraulic means. The height adjustment installation includes at least one device for measuring the surface temp. of the strip. USE/ADVANTAGE - For mfr. of thin strips. The thickness tolerance of strips (with a width-to-thickness ratio in excess of 60) is securely maintained within 2%.