— According to research tests, the rolling-and-drawing of metal in nondriven rollers reduces the rolling force by 30 to 32% as compared with the rolling in driven rollers. A new method of determining the friction coefficient for a modified process flow sheet is proposed. As shown by the calculations, continuous strip mills used in the roll-and-draw mode cut the metal strain force by 34 to 41% and the energy costs of strip rolling by 5 to 13%.

A new method is proposed for determining the frictional index by repeated wire extension. The frictional conditions are investigated with change in the extension, the drawplate taper, and other parameters. A general formula for the frictional characteristics and the drawing stress is proposed. The influence of the lubricant on the friction in deformation of the forgings is shown. Formulas for the frictional characteristics as a function of the form factor are derived. These formulas yield accurate results for the mean normal contact strength.

The potential for decreasing the end thickness of hot-rolled strip in traditional broad-strip rolling mills is demonstrated. The change in thickness depends on the temperature difference over the length of the hot-rolled intermediate strip. Additional reduction of the rear end of hot-rolled intermediate strip is worthwhile for other reasons. The rolling of thinner rear ends of hot-rolled strip in continuous cold-rolling mills decreases the loss of metal in end trimming.

The shaping of strip-mill rollers is analyzed. Industrial experience with supporting and working rollers of particular shape shows that roller wear is reduced and strip rupture is less frequent. The effectiveness of asymmetric profiling of working rollers is assessed, along with its influence on the edge thickness of the strip.

The removal of high-temperature scale from hot-rolled billet is considered. Reducing the bearing rigidity at the supporting rollers permits more effective regulation of the gap between the rollers. New designs are proposed for the plungers of hydraulic roller-balancing devices, working-roller pads with a wedge system, and a universal rolling-mill spindle with mechanical compensation of the gap.

New and traditional hot-rolling mills are compared. Calculations show that the position of the intermediate coiling system in traditional broad-strip mills does not permit sufficient efficiency. A new design is proposed to make better use of the strip temperature, produce strip with negative tolerances, and reduce power consumption.

Research on the energy and kinematic parameters of complex rolling processes is reviewed. Means are proposed for reducing the rolling forces and improving the surface quality of the strip by complex rolling, as well as minimizing roller-replacement rates.

the productimeter) to 0.7-1.1 mm and 0.5-0.9 mm, respectively, depending on the thickness of the rolled strip. The scheme of rolling speed mode in НСХП 1700 (1680) is presented in Figure 1 where Lfe - length of the front end of the rolled strip during threading; Lbe - length of the bottom end of the rolled strip during slowing down the of the mill; Ld and Lc – strip length between the stand № 1 and in the decoiler and in the coiler respectively; Lac, Lsl - strip length during the periods of acceleration and slowing down, respectively; vfe,vs, vbe, vх - rolling speed, respectively, when threading the front end of the strip in the coiler, maximum in the steady process, with the release of the bottom end and the speed corresponding to the intensive change of friction coefficient (for vх < 5 m/sec friction coefficient increases significantly with

Macroshear, reinforced due to local plastic deformation at a workpiece surface in rolls with projections in various directions and shape, may be an effective means of providing high quality rolled sheet. On the example of laboratory studies and industrial tests a favorable effect has been demonstrated for macroshear on mechanical and functional properties of hot- and cold-rolled sheet and strip.

A new expression for definition rolling efficiency in different roll sequences passes accounting roll passes shape influence and correlation between contact resistance in cross and longitudinal direction was obtained. It was determined that the smallest coefficient of effectiveness takes place in rolling sectional bars with free spreading and it rises with increasing of roll pass walls inclination angle.

Reduction of uneven deterioration of roll bodies, broad-strip mill downtime and manufacture of precise transverse section of strip are caused in many respects by application of rational types of grooving of work and back-up rolls in four-high mill stand. Rational roll grooving needs defining the actual length of contact between work and back-up roll. The latter defines sizes of end slopes of back-up rolls and enables to raise accuracy of calculation of work roll natural deflection and values of roll crown out (crown in). The calculation model for determination of rational length of active part of back-up roll body length is suggested in the paper.

The variation of the strain resistance during roll ingotless rolling has been considered; this variation is found to depend on the ratio of the solidification-zone length to the plastic-deformation-zone length, which affects the strain and strain rate. As the metal temperature increases and approaches the solidus temperature, the dependence of the strain resistance on the strain rate becomes much more pronounced. Relations for the calculation of the thermomechanical strain parameters and the strain-hardening exponent are obtained.

To realize a casting-rolling process in two-high units (mills), it is reasonable to maintain a process speed at which the level of the liquid phase does not fall below the level of the plane passing through the roll axes. Dependences are obtained to estimate possible oscillations in the plastic-deformation zone length with allowance for possible deviations of the ingot-rim thickness and to determine the allowable exit strip velocity that provides the required strain.