Analysis of distortion during welding of austenitic Cr-Ni steels by application of Visual Weld software

U ovom radu obrađena je primjena numeričkih simulacija koje se koriste pri zavarivanju zavarenih konstrukcija. Obrađena je i zavarljivost austenitnih nehrđajućih čelika. Objašnjen je mehanizam nastajanja trajnih deformacija i zaostalih naprezanja zavarenih spojeva, te faktori koji utječu na njihovu pojavu. Zatim su analizirani mehanizmi smanjenja zaostalih naprezanja i deformacija u zavarenim konstrukcijama. Na kraju teorijskog dijela navedene su neke komercijalne aplikacije za simulaciju procesa zavarivanja te su opisane njihove mogućnosti. U eksperimentalnom dijelu rada izrađeni su T-spojevi limova od nehrđajućih čelika impulsnim MIG postupkom zavarivanja. Zavarena su dva uzorka, različitim parametrima zavarivanja te je analiziran utjecaj parametara na veličinu kute deformacije. Nakon izrade uzoraka, izvršena je simulacija zavarivanja u programu Visual Weld 11.0, kojom se nastojalo replicirati zavarivanje uzoraka. Napravljena je usporedba rezultata simulacije i stvarnih deformacija te su donešeni zaključci o primjenjivosti programske aplikacije Visual Weld za realne proizvode. The subject of this thesis is the application of numerical simulations used in welding industry. Weldability of austenitic stainless steels is also described. The mechanism of forming of permanent deformation and residual stress of welded joints, along with the factors that influence their occurrence are described. Also, mechanisms of reduction of residual stress and deformation in welded joints are analyzed. Furthermore, commercial applications of welding simulation software and their capabilities are discussed. For the experimental part of the thesis, stainless steel T-joint welds were made using MIG pulsed welding method. Two specimens were welded using different welding parameters and the effect of welding parameters on the magnitude of angular distortion was analyzed. After the specimens were made, simulation of the welding process was carried out using Visual Weld 11.0 software with the objective of trying to replicate the results of welding the specimens. The comparison of simulation results and real deformations was carried out on the basis of which the conclusions were made about the applicability of Visual Weld 11.0 simulation software in real life applications.