CBT welding of zinc coated steels

Završni rad sastoji se od dva dijela, teorijski i eksperimentalni. U teorijskom dijelu opisuje se CBT postupak prijenosa metala, varijante CBT postupka te navedeni su prednosti i nedostatci u odnosu na konvencionalno MIG/MAG zavarivanje. Opisana je metoda zaštite prevlačenjem, prevlačenjem metalne prevlake. Ukratko je opisana priprema površine materijala za prevlačenje. Dan je kratki opis cinka te navedena je primjena pocinčanih prevlaka. Uz to navedeni su postupci nanošenja zaštite cinkovim prevlakama. Opisuje se zavarivanje pocinčanih limova u smislu zaštite na radu, svojstvima i kvaliteti zavarenih spojeva te načinu zavarivanja. Navedeni su i opisani postupci koji se koriste za zavarivanje pocinčanih limova. Nakon obrađenog teorijskog dijela, proveden je eksperimentalni rad. U eksperimentalnom dijelu rada provedeno je lemljenje limova s različitim debljinama zaštitne prevlake cinka. Odabrani su konvencionalni MIG i CBT MIG način rada za istraživanje utjecajnih parametara na kvalitetu lemljenog spoja i na debljinu pocinčanog sloja u blizini zalemljenog spoja. Dobiveni uzorci zalemljenog spoja su makroskopski analizirani.This final thesis is composed from two parts, theoretical and experimental. CBT metal transfer and a modified CBT welding methods are described in theoretical part, also advantages and disadvantages are discribed in relationship with convencional MIG/MAG welding. The protecting coating method is described, protecting with metal coatings. Briefly is described preparation of the material surface for the protecting coating. Besides, procedures for applying zinc coatings are described. Welding of galvanized sheet metal is described in terms of safety at work, properties and quality of welded joints and welding methods. The procedures for welding galvanized sheets are listed and described. After the elaborated theoretical part, experimental work was carried out. In the experimental part, brazing of galvanized steels with different thickness of zinc coating was performed. The conventional MIG and CBT MIG brazing was selected for the study of influence parameters on the quality of the brazed joint and on the thickness of the galvanized layer near the brazed joint. The brazing samples were subjected to macroscopically analysis