Original scientific paper
MODELING OF LUBRICATING LAYER OF STRIP DRESSING WITH THE INFLUENCE OF SURFACE ROUGHNESS
Dušan Ćurčija
; Croatian Metallurgical Society, Zagreb
Marian Buršak
; Technical Univerzitety of košice, Slovakia
Jiri Kliber
; Tehnical Univerzitety of Ostrava, Czech Republic
Abstract
In the paper the influence of transversal roughness of the strip on dressing processes with lubricants is analyzed. The analysis begins with Reynolds differential equation for lubrication, in which transversal roughness of the strip is incorporated. In the estimation, the height of lubricant on the strip is taken into account, as well as its influence on the height of lubricant at the inlet section of the deformation zone. The research has shown that transversal roughness has a twofold influence on the height of lubricant at the inlet section of the deformation zone. If roughness is small of the strip the height of lubricating layer has a tendency of slight decreasing related to the nominal height (when the process is described by smoothness of surfaces) but with an increase of roughness, the thickness of lubricating layer has a tendency to increase. The nominal height of lubricant is considered to be the case of changing the concave surface into the convex one, which seems to look straight as if the process is described by smoothness of surfaces. Lubricating layer modeling in the friction area on insufficiently lubricated surfaces was also performed. The basis of the analysis was the Monte-Carlo numerical method, and an approximate analytical solution, that gave good match in comparison with the numerical method, was established. The results of this theoretical research can clarify some phenomena of lubrication in plastic deformation of metal and the fact that the shape of strip roughness determines the form of lubricating layer.
Keywords
condition of lubricating layer; theoretical model investigation viewpoint; real model investigation viewpoint; strip dressing; plate rolling; roughness of surface; Reynolds' differential equation; Monte-Carlo method; Fourier series
Hrčak ID:
71235
URI
Publication date:
15.7.2011.
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