Markovа M. Improvement of forging processes of the hollow workpieces based on the deformation without a mandrel

Object is technological processes and tools for forging hollow forgings. The purpose - expanding of technological capabilities and improve technical and economic parameters of the hollow forgings producing based on forging process without mandrel. Research methods are a finite element method (FEM), planning of experiment and mathematical statistics, strain measurement, physical and geometric similarity. Theoretical and practical results have been determined: A drawing without mandrel leads to closing of hole workpiece; A geometry tool influences to the workpiece forming; A new method of deformation hollow workpieces without mandrel by dies with bevel has been proposed; A method of designing forging processes, a new manufacturing processes, a mechanical deformation modes and a deforming geometry tool for forging hollow blanks without mandrel have been designed. The novelty of research results: An intensity of workpiece elongation is decreased during forging blanks without hollow mandrel with increasing of workpiece hole diameter; Relations of distribution parameters stress-strain state of the hollow workpiece in depending on different initial ratios workpiece dimensions, reduction ratio, feed and tool geometry have been established; An estimation parameter of workpiece elongation intensity has been proposed; A conceptions of the influence of feed value, angles of cuts and of bevels for dies on forming holes hollow billets have been expanded. The degree of implementation - a new process technology and equipment for forging hollow forgings without mandrel has been implemented. Scope of use is enterprise of heavy and power engineering.