Microstructure, microhardness and chemical composition of a detail obtained by electro-arc surfacing on a hardware-software complex of a delta layout

In the work, electric arc layer-by-layer surfacing of a low-carbon low-alloyed wire in a carbon dioxide environment is carried out. The deposited metal structure in the form of a parallelepiped of thickness 4 mm and height 40 mm reveals the study of microstructure by optical microscopy, the composition of microhardness by indentation of drop tips and chemical composition by atomic emission spectral analysis. The obtained results show that products have a gradient structure. Only the last deposited zone has a dendritic structure. The underlying zones of secondary heat treatment, due to heat release from the upper layer, have a polyhedral recrystallized fine-grained ferritic-pearlitic structure. The microhardness of ejected deposited fibres changes from 1760 MPa to 1360 MPa in upper deposited layers. This is a general decrease in the pearlite fraction and the definition of ferrite. The evaluation of the chemical composition of deposited metal shows that in the first-fourth case, the metal of the deposited wire and substrate metal change, and the percentage of chemical elements in the thickness with the sixth composition of twenty approximately determines the metal of the deposited wire.