Examination of residual stresses in TiN coating on hardened steel 100Cr6

U radu su ispitana zaostala naprezanja koja se javljaju u TiN prevlaci na čeliku EN DIN 100Cr6. Rad se sastoji od teorijskog i eksperimentalnog dijela. U teorijskom dijelu detaljno je obrađena toplinska obrada čelika EN DIN 100Cr6, te njegova mikrostruktura. Obzirom da su uzorci prevlačeni TiN prevlakom opisana su svojstva i primjena prevlake, postupci prevlačenja iz parne faze PVD i PACVD i ispitivanje zaostalih naprezanja na površini prevlaka metodom rendgenske difrakcije. Na kaljenim i popuštenim uzorcima s prevlakom TiN izmjerena je debljina prevlake kalotestom i prionjivost prevlake prema normi VDI 3198. Rendgenskom difrakcijom izmjerena su zaostala naprezanja na površini diska od kaljenog i popuštenog čelika EN DIN 100Cr6 te diskovima s prevlakom PVD TiN i PACVD TiN u tri smjera pod međusobnim kutom od 45°. U svim ispitanim slučajevima nastala su vlačna zaostala naprezanja.. Na površini kaljenog i popuštenog čelika zasotala naprezanja iznose od 150 MPa do 190 MPa, na površini PVD TiN prevlake zaostala naprezanja iznose od 40 MPa do 60 MPa i na površini PACVD TiN prevlake zaostala naprezanja iznose od 115 MPa do 155 MPa.In this thesis, residual stresses that occur in TiN coatings on DIN 100Cr6 steel were examined. The final thesis consists of a theoretical and experimental part. In the theoretical part, the heat treatment of EN DIN 100Cr6 steel and its microstructure are discussed in detail. Since the samples were coated with TiN, the properties and application of the coating, as well as the PVD and PACVD coating processes and residual stress testing on the surface of the coatings using X-ray diffraction, were described. The thickness of the TiN coating and its adhesion according to the VDI 3198 standard were measured on hardened and tempered samples with TiN coating. Using X-ray diffraction residual stresses on the surface of the disk made of hardened and tempered EN DIN 100Cr6 steel, as well as disks with PVD TiN and PACVD TiN coatings were measured in three directions at an angle of 45° to each other. In all cases, tensile residual stresses were observed. Residual stresses on the surface of hardened and tempered steel ranged from 150 MPa to 190 MPa, while residual stresses on the surface of PVD TiN coatings ranged from 40 MPa to 60 MPa, and residual stresses on the surface of PACVD TiN coatings ranged from 115 MPa to 155 MP