Vrvna prižemka je nosilni, dinamično obremenjen konstrukcijski element, ki povezuje sedežno obešalo s transportno vrvjo sedežnice. V lanskem letu smo sistematično vizuelno in defektoskopsko pregledali večje število prižemk in ostalih vitalnih konstrukcijskih elementov sedežnic. Osnovni cilj preiskav je bil oceniti njihovo stanje, detektirati obstoječe razpoke in ostale poškodbe, ki bi lahko vodile do nenadnih lomov ter določili obseg teh poškodb. Ultrazvočna metoda s posebej prirejeno površinsko sondo se je pokazala kot najprimernejša in izredno zanesljiva metoda za določanje razpok na prižemkah. Rezultati preiskav so pokazali, da ima material prižemk in nekaterih drugih konstrukcijskih elementov zelo nizko žilavost in grobo zrnato feritno - perlitno mikrostrukturo, ki je posledica neustrezne toplotne obdelave. Konstrukcijski elementi iz materiala s tako strukturo ne zagotavljajo zadostne odpornosti proti krhkemu lomu.A ropeway clip is an important dynamically loaded construction element that fastens together the hanger bar and the rope. During the last year, we were involved in systematic non-destructive testing of a range of ropeway clips and some other important construction elements. The main goal of the research was to detect the existance of cracks and other types of the damage that can lead to unexpected fracture, and an evaluation of the condition of the ropeway clips. The ultrasound method, accompanied by a specially arranged ultrasound surface beam-probe proved to be the most suitable, precise and reliable method for the cracks detection on the clips. In addition, several laboratory investigations were carried out in order to find causes for the initiation and propagation of cracks in the clips. Results of laboratory examinations revealed that the material of the clips, and also of the other construction elements, had very low toughness and a coarse-grain pearlite-ferritic microstructure, which is a result of improper heat treatment. It was concluded that the construction elements made from material with this kind of structure and mechanical properties would not ensure sufficient resistance to brittle fracture
