20.500.12556/DiRROS-30153 Popravila ulitkov z varjenjem Casting repairs by welding V večini primerov je treba sestavne dele, izdelane z litjem, po proizvodnji popraviti z varjenjem. To velja predvsem za velike ulitke iz jekla. Sicer se z varjenjem popravljajo tudi litoželezni ulitki, vendar po naših izkušnjah napake nastajajo predvsem med delom omenjenih sestavnih delov. So pa popravila ulitkov iz litega železa zaradi njihove krhkosti zelo zapletena. V članku so predstavljeni možni načini popravil z varjenjem in njihova priprava. Na primer, za ulitke iz litega železa obstajajo tri vrste tehnologij za popravila z varjenjem, in sicer s predgrevanjem do vroče, srednje in nizke temperature, kar pomeni, da se razlikujejo temperatura predgretja, način varjenja in material polnila. Tehnologijo varjenja za popravilo je treba izbrati ne le glede na zahteve za popravilo razpok, temveč tudi glede na zahtevano kakovost materiala na območju popravila, ki bo ustrezal delovnim razmeram, kot so dinamični učinek, utrujenost zaradi obremenitev, obraba ali korozija. V večini primerov so pri ulitkih iz jekla po popravilu z varjenjem sestavni deli tudi toplotno obdelani. Trenutna priprava popravil ulitkov s tehnologijo varjenja lahko vključuje sodobne metode, kot so numerična simulacija varjenja, preskusi prototipov in posebno termo-mehansko preverjanje na napravi GLEEBLE. Vsi navedeni sodobni postopki bodo predstavljeni na konkretnih praktičnih primerih tako ulitkov iz jekla kot litega železa. Prikazano bo popravilo ulitka iz jekla kot pokrova turbine iz materiala P91 in optimizacija na podlagi numerične simulacije, kar pomeni, da bo prikazana lokalna struktura materiala, trdota in preostale obremenitve po popravilu. V tem primeru je bila z uporabo stroja GLEEBLE pripravljena lokalna struktura materiala iz toplotno vplivane cone in opravljeni so bili natezni preizkusi, kar pomeni, da so bile ugotovljene lokalne lastnosti materiala. Nazadnje bo prikazano popravilo razpoke v ulitku iz litega železa, ki je del stiskalnega stroja, s polnilom na osnovi niklja, kar pomeni, da je bil opravljen celoten preskus varjenja prototipa ter destruktivno in mehansko preizkušanje, ki je potrdilo zahtevane mehanske parametre. Ključne besede: jekleni ulitek, litoželezni ulitek, popravilo z varjenjem, numerična simulacija varjenja SYSWELD, preizkusi prototipov, termo-mehansko-fizikalno preizkušanje, GLEEBLE, GX23CrMoV12-1, GJS 700-2 In most cases, the components produced by casting have to be repaired using welding technology after production. This mainly concerns large steel castings. However, even cast-iron castings are repaired by welding, but from our experience, defects mainly arise during the operation of the mentioned components. However, repairs of cast iron castings are very complicated due to their brittle behaviour. The article will present possible methods of welding repairs and their preparation. For example, for cast iron castings, there are three types of welding repair technologies as by using hot temperature, middle temperature, and cold. This means the differences are preheating temperature, welding method, and different filler material. The repair welding technology has to be chosen not only accordingarea, which will fit to working conditions as dynamic effects, fatigue loading, abrasion, or corrosion. In most cases for steel casting after welding repair, the steel casting components will also be heat treated. The current preparation of casting repairs by welding technology can include modern methods such as welding numerical simulation, prototype tests, and special thermo-mechanical verification on the GLEEBLE device. All of the above modern procedures will be presented in specific practical cases, for both steel and cast-iron castings. It will be shown one repair of steel casting as turbine cover made from material P91 and optimisation based on numerical simulation, that means it will be shown local material structure, hardness, and residual stresses after repair. Also, in this case, by using the GLEEBLE machine, the local material structure from heat-affected zone has been prepared, and the tensile tests have been done, which means there has been identified local material properties. The last repair of the crack in the cast iron casting, it is part of a press machine by nickel-based filler material will be demonstrated which means the complete prototype welding test and destructive and mechanical testing have been done and have confirmed receiving the required mechanical parameters. Keywords: steel casting, cast iron casting, welding repair, SYSWELD welding numerical simulation, prototype tests, thermo-mechanical-physical testing, GLEEBLE, GX23CrMoV12-1, GJS 700-2 ulitki varjenje popravilo mehanske lastnosti litine jeklo true false false Angleški jezik Slovenski jezik Neznano 2026-06-16 11:10:33 2026-06-16 11:10:33 2026-06-17 03:46:50 0000-00-00 00:00:00 2026 0 0 Besedilo v slov in angl.; str. 10-24 št. 1 Letn. 73 2026 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 2026-01-01 621.791:621.74 0024-5135 281717251 Casting_Repairs_by_Welding_Livarski_vestnik_letnik_73_no_1-2026_10-24.pdf Casting_Repairs_by_Welding_Livarski_vestnik_letnik_73_no_1-2026_10-24.pdf 1 5E2B45C8C725DCFBB346A54F7727A2F1 f2c605651af7f7a974063c0fb7b4d3da71a364a37a1e23e85fc06b5ba1839270 63d14ab2-6963-11f1-97b2-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=45614 Društvo livarjev Slovenije Livarski vestnik 0 0 0