PECULIARITIES OF STRUCTURE OF COATINGS OF Fe-Cr-Al SYSTEM FLUX-CORED WIRE PRODUCED UNDER CONDITIONS OF SUPERSONIC ELECTRIC ARC METALLIZATION

摘要

To increase the efficiency of application of method of supersonic electric arc metallization (EAM) the investigations of structure and phase composition of coatings of flux-cored wire of the system Fe-Cr-Al were carried out in the frames of this work. Presented are the results of investigations of coatings produced by EAM method using the conventional and modified installation EM-14 and also installation PLAZER 15-SA for supersonic electric arc spraying. It is shown that use of supersonic gas jets at EAM allows significant improvement of coating quality, i.e. provides higher level of homogeneity and fine dispersion of structure (the thickness of lamellas is decreased from 10-30 to 5-10μm), decreases porosity by 3-5 times, decreases oxides content by 2-3 times, 30-50 % increases the hardness. The formation of solid solution of chromium and aluminium in iron with increased content of chromium at supersonic EAM is a precondition for ensuring the heat resistance of developed coatings of up to 1350℃, which allows considerably expanding the scales of application of this method in deposition of protective coatings.