THE EFFECT OF MICROSTRUCTURE ON TOUGHNESS OF STEELS

U ovome radu je opisano što je to krhki lom, zašto i kako on nastaje, koji su problemi krhkog loma te kako ga spriječiti. Opisan je utjecaj mikrostrukture i temperature na žilavost čelika, točnije koji legirni elementi daju dobra svojstva žilavosti, a koji je smanjuju, te pri kojim temperaturama se čelik ponaša žilavo, a na kojima krhko. Za ocjenu žilavosti opisana su razna ispitivanja, gdje svako od ispitivanja ima svoj način provođenja i način zapisivanja rezultata, te ocjene žilavosti. U eksperimentalnom dijelu provedeno je ispitivanje na čeliku, Charpyjevom metodom ispitivanja žilavosti. Opisan je proces početka ispitivanja, pripremni alati, pa sve do kraja i zapisivanja rezultata. Ovaj rad je temelj za početak učenja o tome što je to žilavost. Detaljnim opisom svakog poglavlja, svakome tko bude čitao ovaj rad dobro će pomoći u usavršenju već prethodnih znanja.This work describes what is fragile fracture, why and how it is produced, what problems are with fragility of a break and how to prevent it. The influence of microstructure and the temperature on steel toughness is described, more precisily, what alloy have good toughness properties, which alloy reduces fragility, and at which temperatures the steel acts tough or fragile. To evaluate the toughness, various tests are described, where each of the examinations has it own way of carrying out and how to record results, and how to evaluate the toughness. In the experimental part, a steel test was carried out using Charpy impact test method. The test start-up process is described, the preparatory tools, the ending and writing of the results. This work is the basis for the beginning of learning about what is toughness, with a detailed description of each chapter, anyone who reads this work will be helped in the improvement of previous knowledge