FEATURES OF DEFECTS WHEN ROLLING THIN STRAPS AND FOILS

Abstract

The authors analyze the main causes of their formation and methods preventing the appearance of scrap. Correct selection of necessary modes of strip rolling is complicated due to the peculiarities of the rolled material with shape memory – nitinol. Titanium nickelide has the ability to attach gases (nitrogen, oxygen) and is subject to oxidation. The article deals with defects formed during rolling on multi-roll mills. Among them are double-sided corrugations, boxiness, bubbles, waviness, different thicknesses. The main negative factors that are sources of these defects can be counteracted by correct roll profiling (waviness), setting the right modes of compression (double-sided corrugation), reassembly of the main units of the mill (runout, boxiness). When rolling hard-to-machine materials, sliver texture should be analyzed to identify sources of defects. Rolling equipment adjustment should include not only rolling modes (speed, compression value, tension on coiler drums), but also work with working rolls, including high-precision surface treatment of barrels and necks.