The Influence of the Diffusion on Adherence of the 60T Deposits Obtained by Thermal Spraying in Electric Arc

Abstract

The physic-chemical and mechanical properties of steel deposits obtained by thermal spraying depend on technological parameters of the spraying process. Generally, wear resistance of the deposits depends on the degree of porosity and the adhesion of the layer to the substrate. In the case of the deposits obtained by spraying, studies have shown that between deposited layer (SD) and substrate (S) there are the following types of adhesions: mechanical, metallurgical, superficial, physical and diffusive. Each type of adherence, enumerated above, works through a well-defined mechanism so that it can be said that the adhesion of the obtained deposits by thermal spray is a sum of mechanisms which interacting. How these mechanisms interact, as well the percentage of the influence is determined by: operating parameters, by the deposit material and thermal treatments after the deposit obtaining. This paper proposes to determine the influence of thermal treatment on adherence of 60T deposits obtained by thermal spraying in electric arc- as a thermal processing method after metallization. The assessment of adherence deposit 60T - in two ways, according to with EN 582 and DIN 27201/2005 in conjunction with the investigations of electron microscopy (SEM), XRD analysis, and image analysis performed at both the zone: Coating - Interface - Substrate (CIS) has revealed the presence of diffusion and the structural constituents. The graphs of adherence variation for 60T deposits with the concentration gradient of the alloying elements of the 60T layer respectively of adherence layer (75B) obtained experimentally by investigations carried out on the substrate have demonstrated the role of the secondary thermal treatment on the deposit adherence.