High-strength alloys based on nickel with added tungsten are characterized by high resistance to deformation and very low plasticity. Accordingly, it is very important to determine the rational range of hot pressure treatment (including screw rolling) of these alloys. Intense deformational heating is very important in rolling high-strength alloys. At the same time, heat transfer by the working rollers and to the atmosphere occurs in the deformation source. The surface temperature of the rolled rod is significantly higher than the temperature at its center, on account of the low heat conduction of the alloy, the nonuniformity of deformation, and the intense slip of the metal relative to the rollers. As a result of such hot transfer, the maximum rod temperature over the radius is observed at a depth of 3-5 mm from the surface, where annular failure occurs, especially with large reduction per pass (Fig. 1).
展开▼
