Effect of asymmetric material entrance on lubrication in cold rolling

• Published in: Tribology international 2022-11, Vol.175, p.107810, Article 107810
• Main Authors: Jacobs, L.J.M., Dam, K.N.H. van, Wentink, D.J., Rooij, M.B. de, Lugt, J. van der, Schipper, D.J., Hoefnagels, J.P.M.
• Format: Article
• Language: English
• Subjects: Cold rolling; Digital image correlation; Lubrication; Steel
• ISSN: 0301-679X; 1879-2464
• DOI: 10.1016/j.triboint.2022.107810

An Integrated Digital Image Correlation (IDIC) method has been applied to the cold rolling process, the images clearly visualise the geometry of the roll bite and the inlet zone. A key, novel finding is that despite using coils and applying entry tension, the strip can enter asymmetrically in the rolling mill. Moreover, it is shown that asymmetric strip feeding results in an uneven lubricant film thickness between top and bottom strip surface. A method is detailed to feed the strip truly symmetrically in the mill, a procedure that is necessary for a meaningful experimental validation of lubricant film thickness models. For symmetric rolling processes the measured film thickness corresponds significantly better with the theory than for asymmetric processes. [Display omitted] •Observation and root cause analysis of asymmetric material entrance in rolling mill.•Demonstration of the impact of asymmetry in the rolling process on lubricant film thickness.•Experimental lubricant film thickness for symmetric process in good agreement with theory.•Experimental validation of contact length, strain and velocity fields with IDIC.