Performance of solution-type lubricants in rolling of stainless steel --solution-type cold rolling lubricants I--

摘要

In order to develop a uniform rolling lubricant with fire resistance and high cooling efficiency, the performance of solution-type lubricants containing water-soluble polymers is evaluated and compared with those of neat-type and emulsion-typelubricants, in rolling of stainless steel. Solution-type lubricants exhibit superior lubricity, especially at high reduction, compared with the other types of lubricants. The strips rolled with solution-type lubricants show lower surface brightness thanthose rolled with neat-type lubricants at low reduction; however the opposite is true at high reduction. The performance of solution-type lubricants is attributed to the following: (1) the very low viscosity of water at high pressures is responsible forthe very low shear stress of its liquid film within the contact arc compared with that of neat oil, (2) the liquid film becomes thick because of viscosity increase caused by heat separation of polymers around work rolls, resulting in reduced contactratio, and (3) water prevents the formation of microscratches because it cools the heat spots generated between roll and strip surfaces.