Merjenje zaostalih napetosti v zvarih na dupleks nerjavnih jeklih

Muhič, Krystijan (author), Klobčar, Damjan (mentor), Trdan, Uroš (comentor)

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.

• Language: Slovenian
• Keywords: varjenje, zvar, TIG varjenje, dupleks nerjavna jekla, mikrostruktura, zaostale napetosti, nevtronska in rentgenska difrakcija, mehanske lastnosti
• Work type: Final paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: FS - Faculty of Mechanical Engineering
• Place of publishing: Ljubljana
• Publisher: [K. Muhič]
• Year: 2022
• Number of pages: XIV, [29] f.
• PID: 20.500.12556/RUL-142256
• UDC: 621.791.725(043.2)
• COBISS.SI-ID: 137043203
• Publication date in RUL: 28.10.2022

MUHIČ, Krystijan, 2022, Merjenje zaostalih napetosti v zvarih na dupleks nerjavnih jeklih [online]. Bachelor’s thesis. Ljubljana : K. Muhič. [Accessed 2 April 2025]. Retrieved from: https://repozitorij.uni-lj.si/IzpisGradiva.php?lang=eng&id=142256

Secondary language

• Language: English
• Title: Residual stress measurments of lean duplex stainless steel welded sections

Abstract

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.

• Keywords: welding, weld, TIG welding, duplex stainless steel, microstructure, residual stress, neutron and X-Ray diffraction, mechanical properties