Improvement of a manufacturing technology of large forgings based on using of a new upsetting method
DOI:
https://doi.org/10.37142/2076-2151/2020-1(50)91Keywords:
forging, upsetting, ingots, internal defect, massive part, four-beam workpiece, concave faces, FEM, parameter of the stress state, compressive stresses.Abstract
Markov O. E., Zlygoriev V. N., Ivanova U. O., Lager A. O., Dorofeev V. A. Improvement of a manufacturing technology of large forgings based on using of a new upsetting method. Material working by pressure. 2020. № 1 (50). Р. 91-97.
An upsetting method of massive ingots has been investigated. Proposed method consists in the upsetting of profiled workpieces with concave faces. A technique of theoretical investigations by finite element method has been designed. This technique assumed an establishment of dependencies for internal defects closing. An angle of the concave faces was 150°. A relative depth of the concave faces was varied in range 15 %…25 % from workpiece`s diameter. Strains effective and mean stresses in the longitudinal cross-section of the workpiece after upsetting have been determined. A value of compressive stresses was determined based on a parameter of the stress state. Theoretical investigations allowed to determine a distribution of stresses and strains into body of the four-beam workpieces after upsetting. Finite element modeling allowed to found a rational depth of the concave faces which has to be 15 % from workpiece`s diameter. A maximal closing of the internal defect take place for this depth of the concave faces. Obtained results are explained by parameter of the stress state, which shows an appearing of the compressive stresses due to support of the concave faces. Results of the Finite element modeling were tested by experimental investigations. An approbation of obtained results was realized on real steel forgings. It were established that upsetting of the four-beam workpieces increased a quality of the massive parts.
