Hodnocení korozní odolnosti niklových slitin

Abstract

The theme was focused on corrosion resistance evalutation of centrifugal casted experimental nickel alloy - type Alloy 625 (Ni–Cr–Mo–Nb). Main task of the theme was verification of susceptibility of the casting made from mentioned material against intercrystalline corrosion in dependence on heat treatment or undesirable heat affection. Attention was focused on material specification of produced casting, it was evaluated an influence of heat treatment on basic mechanical properties and microstructure of experimental alloy. A fundamental part deals with evaluation of resistance of testing specimens against intercrystalline corrosion given by exposure tests in solution of sulphuric acid with ferric sulphate and nitric acid solution. Performed experiments have confirmed lower corrosion resistance of the casting material in comparsion with as wrought state and demonstrated essential influence of solution annealing on inhomogenity and properties of the casting.