Tribological behavior of polyoxymethylene in water-lubricated friction against steel

The paper presents the results of testing of block specimens of polyoxymethylene in water-lubricated sliding boundary friction against steel. Under these testing conditions, the polymer shows a combination of good antiwear and antifriction properties. With the addition of 1 wt % of fullerene soot to the polyoxymethylene, its wear rate declines considerably, while its friction coefficient remains quite low; its carrying capacity is high and the wear process is stable. The friction coefficient, wear rate, and carrying capacity of modified pilyoxymethylene are compared to those of carbon plastics under similar testing conditions.     

Heat-Generating Composite Material: Fe Oxidation in Fibers of a Polymer Matrix

A method is devised for the fabrication of composite materials in which heat-generating mixtures (Fe powder, activated carbon, water, and additives) are incorporated into polymer fibers. The air oxidation of Fe in such materials is studied. The results demonstrate that the thermal and mechanical properties of the composite depend on the fabrication conditions, filler composition and content, physicochemical properties of activated carbon, and some other factors. The caloric value of the composite is 2360 J per gram of Fe.     

Modernizing the pipe-electrowelding shop at OAO VTZ

The range of large-diameter pipe produced at OAO VTZ has been expanded, with increase in the wall thickness and the introduction of higher strength classes. A new production department for the manufacture of straight-seam pipe has been introduced at OAO VTZ; this pipe is intended for use in pipelines. A state-of-the-art production technology for high-quality pipe has been adopted, so as to comply with the highest current requirements.     

Model of Turbulent Oscillating Flows in Smooth Tubes

Turbulent oscillating flows in smooth tubes are considered. A group of flows in which the logarithmic boundary layer grows monotonically with time is distinguished; the conditions of quasistationarity of these flows are determined. A model of a quasistationary turbulent oscillating flow in a smooth tube is constructed; the model is in satisfactory agreement with experiment.