20.500.12556/RUL-142256 Merjenje zaostalih napetosti v zvarih na dupleks nerjavnih jeklih Residual stress measurments of lean duplex stainless steel welded sections Zaostale napetosti se pojavljajo pri skoraj vseh proizvodnih procesih, kjer v material vnašamo energijo in vplivajo na življenjsko dobo izdelka. Zaključna naloga temelji na teoretičnem pregledu in sicer se osredotoča na zaostale napetosti, ki nastanejo v zvarih na dupleks nerjavnih jeklih. Obravnavani bodo varjeni kvadratni in H-profili iz vitkega dupleks nerjavečega jekla. Meritve natezni in tlačnih napetosti so bile opravljene z nedestruktivno metodo nevtronske difrakcije, Izvedena je bila analiza trdote in mikrostrukturna karakterizacija z optično mikroskopijo in difrakcijo s povratnim sipanjem elektronov. S tem je bil ugotovljen volumenski delež posamezne faze in preračunane zaostale napetosti. Največje natezne zaostale napetosti varjenih kvadratnih profilov so bile opažene v bližini zvarov, in sicer za vzorec S-1 in S-2. Pri H-profilu pa so bile največje zaostale napetosti opažene na sredini razpona stranskih plošč in na obeh koncih prirobnice. Residual stresses appear in almost all production processes where energy is introduced into the material and affect the product's lifetime. The final thesis is based on a theoretical review and focuses on residual stresses that occur in duplex stainless steel welds. Welded square and H-profiles made of slender duplex stainless steel will be considered. Tensile and compressive stress measurements were performed using the non-destructive neutron diffraction method. Hardness analysis and microstructural characterization were performed using optical microscopy and electron backscatter diffraction. With this, the volume fraction of each phase and the calculated residual voltage were determined. The highest tensile residual stresses of the welded square profiles were observed near the welds, namely for sample S-1 and S-2. For the H-profile, however, the highest residual stresses were observed at the mid-span of the side plates and at both ends of the flange. varjenje zvar TIG varjenje dupleks nerjavna jekla mikrostruktura zaostale napetosti nevtronska in rentgenska difrakcija mehanske lastnosti welding weld TIG welding duplex stainless steel microstructure residual stress neutron and X-Ray diffraction mechanical properties true false false [K. Muhič] Slovenski jezik Angleški jezik Zaključna naloga 2022-10-28 08:30:28 2022-10-28 08:30:32 2023-10-13 08:55:15 0000-00-00 00:00:00 2022 0 Ljubljana 0 XIV, [29] f. 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 621.791.725(043.2) 246725 137043203 20818.pdf 20818.pdf 1 7411CB284D7273FE7363C3A17176E9BD 4f3a5351c03367645e098ae3fe5bb7e42f692555d3570bbefc4db382aa024991 f32ab4a2-5689-11ed-9c94-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=163565 Fakulteta za strojništvo 0 0 0