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Namen magistrske naloge je bil, podrobneje spoznati postopek varjenja s plazmo ter ugotoviti vpliv uporabe aktivnega praška za povečanje globine prevaritve, pri čemer takrat govorimo o tako imenovani "A – plazmi". Uporabili smo dva aktivna praška različnih proizvajalcev. Za lažje primerjanje učinkovitosti aktivnega praška, smo med sabo zavarili tri nerjavne pločevine enakih dimenzij, debeline 6 mm. Prva je bila zavarjena brez uporabe aktivnega praška, ostali dve pa z uporabo praška. To smo storili tako, da smo polovico plošče premazali z enim, drugo polovico pa z drugim praškom. Nekoliko smo variirali še z uporabo dodajnega materiala. Po natančnem razrezu pločevine za mehanske preizkuse, smo le te opravili. Preizkusili smo trdnost, žilavost, sposobnost upogiba, trdoto ter pogledali mikrostrukturo obrusov. Vse preizkuse smo opravili na Fakulteti za strojništvo v Mariboru. Dobljene rezultate smo ovrednotili in jih med seboj primerjali. Po izrisu diagramov in primerjanju vrednosti smo ugotovili, da so vsi vari preizkušanje uspešno prestali, kar je podrobno pokazala tudi analiza mikrostrukture. Vpliv na rezultate je imela tudi uporaba dodajnega materiala. To nam pove, da uporaba aktivnega praška na nerjavni pločevini, pri še ne kritičnih debelinah pločevine le minimalno prispeva k izboljšanju mehanskih lastnosti in ni nujno potrebna. The aim of this master thesis was to be better informed about plasma welding and note if the use of active powder has any influence on weld penetration. This process of welding is known as "A – plasma" welding. We used two different active powders from different manufactures. For better effectiveness comparison of the use of active powder, we welded together three identical stainless steel plates, from thickness 6 mm. The first plate was welded normaly, without using active powder, but other two were welded by "A-plasma" welding. The first half of plate was covered with green and the last half with white active powder. We varied also with filler rod. After the exact cutting of welded stainless stell plates, we made several mechanical tests. This includes strength testing, impact tougness, ability to bend, hardness and check of microstructure. All tests were made in Faculty of Mechanical Engineering in Maribor. All obtained results were evaluated and compared. After drawing all diagrams and value comparison we found out, that all of stainless steel plates were succsessfull welded. This was verified from microstructure check. The influence on results value, contributed the filler rod also. From this unexpected results we found out, that any kind of use of active powder on stainless steel plates are unnecessary. Mechanical properties chance only a little bit. |
