Ural Federal University (Ekaterinburg, Russia):

Korobov Yu. S., Dr. Eng., Prof., Head of the department, e-mail: yukorobov@gmail.com

Research & Development Enterprise “Mashprom” (Ekaterinburg, Russia):
Kotelnikov A. B., Chief Manager

EVRAZ Nizhniy Tagil Metallurgical Works (Nizhniy Tagil, Russia):
Kushanrev A. V., Dr. Eng., Managing Director
Kirichkov A. A., Cand. Eng., Advisor

Abstract: Resource of continuous casting moulds is limited by the wall resistance. The walls made of bronze, with micro-alloying by silver or zirconium, which are characterized by high heat conductivity in combination with low loss of strength during cyclic heating, are usually used. Different coatings made of nickel- and chromium-base alloys are deposited on the walls in order to rise wear resistance. The structure of the samples made of CuCrZr bronze with chromium-nickel coating, applied by HVAF spraying, has been studied using metallographic and micro-X ray spectral analysis. Development of mutual diffusion of base and coating atoms, as well as recrystallization in sub-boundary base sections are shown in this paper. It finalizes in forming the transition area with size not less than 20 μm both in coating and in base. Lowering of recrystallization temperature of a base surface leads to forming of the layer with lowered strength properties; however, it provides increase of adhesion strength in coating and rise of its resistance during thermocycling. The mechanism of forming the transition area, connected with the features of the force effect during dynamic hitting of spraying particles with metal base in the process of coating HVAF spraying is suggested. The obtained results have been used in development of the technology for spraying coating on mould walls.

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