Contrast Study On Roller Friction And Wearing Conditional Fatigue Life

Roller is the important tool and is one of expendable parts in rolling. A lot of practices proved that the wear and contact fatigue is the main reason of roller's invalidation. The quality of roller especially the inherence quality affected the tools' wastage and produce cost, and at the same time, it is very hard to control the product quality due to that the wear and contact fatigue destroy the beginning roller model. So the systems analysis of the roller's wear mechanism and contact fatigue and the research of contact stress and wear rule have the important meaning on controlling geometry precision ,the board form and surface quality and prolonging the roller's using life.Consult the Hertz theory, based on the engineering background of the roller of steel rolling, researching the contact problem of two long parallel cylinders and considering the infection of friction. Gained the stress expressions when the vertical load and the friction act on the rolls separately, then according with superposition theorem of elastic mechanics, gained the stress expressions with the contact pressure and the friction force combined action.There are three rows of samples which have been dealt with by three different surface craftworks. They carry through the wear experiment and the fatigue flake experiment, under the same loads, the same rotate speed and the same circumstance, then assessed the fatigue wear level, filter the first-rank surface treating craftwork. Through the wear experiment and fatigue flake experiment, gained three rows of wear capacities, fitting curves of quality-time, using electron microscopic autoradiography shooting the image wear and flake pictures and then determine the most wear resistant surface treating craftwork sample.In engineering practice, generally using Hertz theory obtaining the biggest contact stress, all appearance, it has limitation. Between the roller and rolling stock, there are normal component of contact force but also tangential frictional force .this article's achievement is that using the acknowledge of elastic mechanics, consideringthe infection of friction, amended the Hertz contact formula and supply the theory gist for the research and improvement of rollers. At the same time, this article combine the engineering practice, gained the optimum rollers' surface treating craftwork, these have important guiding meaning. Some conclusions were summarized and the problems that should be studied further were put forward in the end of the dissertation.