Matematický popis středního přirozeného deformačního odporu oceli 42CrMo4 za tepla

Abstract

The aim of this bachelor thesis is to find a sufficiently precise mathematical description of the mean natural hot flow stress of steel 42CrMo4. The bachelor thesis is divided into theoretical and experimental part. The theoretical part deals with the theory of natural and mean natural flow stress, forming tests, stress-strain curves, the influence of the Zener-Hollomon parameter and mathematical models describing the hot flow stress. The experimental part describes the used Gleeble 3800 with an additional module on which the uniaxial compression test was performed. Last but not least, the steel 42CrMo4 is characterized and the uniaxial compression test is described. In this part, it is also dealing with the calculation of the mean-natural-flow-stress value and the mathematical description of the mean natural flow curve using simple mathematical dependencies. Furthermore, the applicability and accuracy of simple equations in flow curve description were evaluated.