INCREASING THE DENSITY OF PEAKS MICROGEOMETRY OF AUTOMOBILE SHEET DUE TO IMPROVEMENT OF THE SHOT-BLASTING UNIT DESIGN

Abstract

The research of the eff ect of installing the redesigned iron curtains in the turbine of the shot blasting machine (SBM) for notch of the work rolls surface was carried out for the temper mills “1700” and “2500” of sheet rolling shop – 5 of OJSC “MMK”. Curtains were installed in a plane perpendicular to the plane of rotation of shot blast wheel mounted in a turbine. The sizes of the curtains and place of the installation were determined, providing increased density of shot torch at notch of rolls with minimal shielding action of split shot bounces off the iron curtains. The researches have shown that a fraction speed after collision with a curtain changes not only the direction but also the magnitude. Change of direction and speed reduction of the shot after the collision with the curtain depends on the friction conditions between the shot surface and curtains, as well as the angle of attack. Shot blasting machine modernization provided opportunity to increase the density of shot torch peaks on the surface of work rolls of temper mill, and thus to increase also the density of a trained metal peaks at 1.22 times compared with metal, trained before the improvement of shot blasting machine design.