The influence of mechanical properties of steel pressure vessels on crack appearance at tensile loading

V diplomskem delu so opisane in predstavljene vrste jekel, ki se najpogosteje uporabljajo za izdelavo tlačnih posod ter dva mehanizma loma v kovinah, in sicer cepilni ter žilavi lom. Predstavljene so tudi nekatere najpomembnejše lastnosti jekel in natezni preizkus, s katerim določamo te lastnosti. V sklopu izdelave diplomskega dela je bil opravljen tudi natezni preizkus ter kemijska analiza uporabljenih materialov. Z izvedbo nateznega preizkusa smo želeli primerjati mehanske lastnosti dveh različnih materialov ter poiskati vzroke za nastanek razpoke in prelom materiala. S pomočjo posebne kamere smo zabeležili spremembe naših preizkušancev ter določili mesto in začetek nastanka razpoke. Po končanem nateznem preizkusu je sledila priprava vzorcev za mikroskopijo ter pregled prelomnih površin in vzorcev pod mikroskopom.The diploma thesis describes and presents the types of steels that are most commonly used in the manufacture of pressure vessels. Some of the most important properties of steels and mechanisms of fracture are presented as well as a tensile test to determine these properties. As part of the diploma work, a tensile test and chemical analysis of the materials were also performed. By performing a tensile test, we wanted to compare the mechanical properties of two different materials, and to find the causes of crack formation and material fracture. With the help of a special camera the changes of our subjects were recorded. Tensile test was followed by examination of fracture surfaces under the microscope