CRANKSHAFT FORGING, TAKING INTO ACCOUNT THE IMPACT OF DEFORMATION MODES ON THE QUALITY OF FORGINGS

Abstract

The study addresses an approach to improving the free forging technology of crankshaft forgings by analyzing the uneven distribution of deformation within the workpiece volume. The relevance of the research is driven by the need to enhance the uniformity of mechanical properties of parts, minimize internal defects, and reduce metal and energy consumption. One of the critical stages is the metal transfer process during free forging, which is often accompanied by an uneven distribution of plastic deformation, leading to internal stresses and distortion of the workpiece. Using the “swage” tool, it is possible to purposefully control local metal stresses and direct metal flow for subsequent operations, contributing to a more uniform distribution of plastic deformation. The application of the swage increases the homogeneity of the forging structure, reduces the risk of internal defects and distortions, and optimizes the energy consumption of the process. To evaluate the nature of deformation, a method for determining the unevenness of plastic deformation based on the analysis of cross-sections of the forging was applied. The methodology involves identifying areas with maximum deformation intensity, allowing the investigation of the stress-strain state. The obtained results made it possible to establish the relationship between tool geometry, deformation parameters (temperature, degree of deformation), and the nature of deformation distribution. This approach allows for predicting critical zones, justifying the selection of forging modes, and adapting the technology to the specific features of individual parts, which contributes to reducing forging distortion, increasing structural uniformity, and improving technological heredity. The research results can be used to design effective free forging processes for critical parts, particularly crankshafts, with predictably stable operational properties.