Heat treating process of workpiece LM.22-DT.57

U ovome radu govoriti će se o poboljšavanju čelika. Izvršeni je odabir parametara toplinske obrade kako bi se postigli postavljeni zahtjevi u vidu tvrdoće čelika. Prvi dio rada, odnosno poglavlja 1. i 2. obuhvaćaju teorijski dio postupka poboljšavanja. Poboljšavanje je razlučeno na dva procesa: kaljenje i popuštanje. U potpoglavljima Kaljenje i Popuštanje postavljena je teorijska osnova navedenih postupaka te mikrostrukturne promjene koje se događaju, kao i način odabira parametara toplinske obrade. Isto tako svaki proces upotpunjen je s tablicama i dijagramima koji potkrepljuju teorijski dio. Nadalje, u teorijskom dijelu obrađeni su i čelici za poboljšavanje. Definirana su mehanička svojstava te najčešće grupe čelika za poboljšavanje kao i njihova svojstva i primjena. Uz to, postavljena je i tablica najčešćih čelika za poboljšavanje te pravilan odabir istih temeljem njihove dimenzije i konvencionalne granice razvlačenja. Konačno, u poglavlju 4. objašnjen je postupak provedene toplinske obrade. Objašnjen je zahtjev kojeg je potrebno zadovoljiti. Definiran je predmet podvrgnut toplinskoj obradi uz parametre koji su bili potrebni za provesti toplinsku obradu te je nakon toga izvršena kontrola tvrdoće. Uz to objašnjena je i vrsta korištene opreme.Thesis of this paper is steel “improvement“. The selection of heat treatment parameters was made in order to achieve the set requirements in the form of steel hardness. The first part of the paper, i.e. chapters 1 and 2, cover the theoretical part of the improvement process. Steel improvement is distinguished into two processes: quenching and tempering. In the sub-chapters Quenching and Tempering, the theoretical basis of these procedures and microstructure changes that occur are set, as well as the way of selecting the parameters of heat treatment. Likewise, each process is completed with tables and diagrams that corroborate the theoretical part. Furthermore, in the theoretical part, improvement steels are also defined. The mechanical properties of this most common group of steels for improvement as well as their properties and application are defined. In addition, a table of the most common steels for improvement and proper selection of them based on their dimension and conventional yield strenght has been set up. Finally, Chapter 4 explains the heat treatment procedure that has been carried out. The request that needs to be met is explained. Object which was subjected to heat treatment was defied as well ast he parameters that were necessary for the heat treatment and after that the hardness control was carried out. In addition, the type of equipment used is explained