INFLUENCE OF PREHEATING TEMPERATURE ON THE QUALITY OF WELDED JOINTS

U ovom radu su opisani najčešće upotrebljavani postupci toplinske obrade, dok je postupak toplinske obrade predgrijavanja detaljnije opisan. Također su opisani i konstrukcijski čelici, njihove oznake te zašto se oni najviše koriste u strojarstvu. U eksperimentalnom dijelu je opisana izrada uzoraka, njihovo zavarivanje MIG/MAG 135 postupkom zavarivanja, njihova daljnja obrada te mjerenje tvrdoće. Osim toga detaljno je opisana oprema kojom se provodi toplinska obrada i oprema koja se koristila u eksperimentalnom dijelu. Tekst je obrazložen pomoću slika, dijagrama i tablica u kojima su dani i između ostaloga rezultati mjerenja u eksperimentalnom dijelu. Prema dobivenim rezultatima mjerenja doneseni su određeni zaključci.This paper describes the most commonly used heat treatment procedures, while the preheating heat treatment procedure is described in more detail. Structural steels, their markings and why they are mostly used in mechanical engineering are also described. The experimental part describes the creation of samples, their welding with the MIG/MAG 135 welding process, their further processing and hardness measurement. In addition, the equipment used for heat treatment and the equipment used in the experimental part are described in detail. The text is explained using pictures, diagrams and tables in which the results of measurements in the experimental part are given, among other things. According to the measurement results, certain conclusions were drawn