Fatigue of nodular cast iron at high frequency loading

Abstract

The paper deals with the influence of charge composition on microstructure of nodular cast iron and its fatigue properties at high frequency loading. The basic charge of experimental melts was formed by a different ratio of pig iron and steel scrap. Chemical composition of individual melts was regulated alternatively by metallurgical silicon carbide (SiC) or ferrosilicon (FeSi) and carburizer. Fatigue tests were realised at high frequency sinusoidal cyclic push-pull loading (stress ratio R = -1) at ambient temperature (T = 20 ± 5°C). High frequency fatigue tests were carried out with using of the ultrasonic fatigue testing device KAUP-ZU (frequency f ≈ 20 kHz).The results show differences in mechanical and fatigue properties, which are connected with the microstructure. SiC additive positively influences microstructure and consequently, mechanical and fatigue properties of nodular cast iron are improved.

Optimization and design of the vulcanization press sandwich pressure plate parameters

“…• evaluation of results -determination of weight, maximum equivalent stresses according to von Mises theory, maximum plate deflection and evaluation of fulfillment of the conditions according to relations (2) and (3) [18,19], • in the event of non-fulfillment, the target function is penalized, otherwise the target function value is determined based on the calculated weight of the structure. The shape of the target function according to equation (5) and its evaluation procedure is suggested for the following reason -if the geometric constraints for the area of permissible solutions (4) are not met, the FEM analysis is not required.…”

“…This approach will be applied to a specific construction in the article [3,4,5]. https://doi.org/10.1051/matecconf/201824401005 ITEP' 18…”

Yield and fracture loci for a ductile cast iron EN‐GJS‐600–3 under biaxial stresses

“…In 1948, it was discovered that the addition of small amounts of magnesium (Mg) induces the precipitation of graphite in the form of nearly spherical nodules dispersed in a matrix that can be ferritic, pearlitic, bainitic, or a combination of them depending on the alloy formulation, the casting control, and the final heat treatment 5,6 . This nodules' shape attenuates the stress concentration induced on the surrounding matrix and thus confers high ductility 7,8 and good fatigue properties 9 . For this reason, DCI is nowadays employed in moderately stressed components of complicated shapes and large dimensions with structural functions 10–12 …”

Parallelization of computational algorithms for optimization problems with high time consumption

“…It is necessary to implement several types of analyses based on FEM for complex optimization problems solving (stress analysis to determine the state of stress distribution, modal-frequency analysis to determine the natural frequencies, loss of stability analysis, etc.) [3,4].…”