Influence of surface roughness and current intensity on the adhesion of high alloyed steel deposits - obtained by thermal spraying in electric arc

Abstract

In this paper the surfaces of some steel samples, low alloyed, were covered by electric arc thermal spray with a steel layer, high alloyed, containing FeNiCrSiB-WC/TiC, using a core wire. In order to study the influence of process parameters on obtained deposits, the surface roughness and the intensity of electric current varied on three levels and the rest of the technological parameters were kept constant. The microstructural characteristics, chemical composition, physical and mechanical properties of the obtained deposits were investigated by SEM analysis of microhardness and by X-ray diffraction. The deposition porosity was investigated by optical microscopy. The adhesion of the layers was investigated by the traction test. Studies have shown that by increasing the intensity of the electric current respectively the arc temperature, the deposition porosity decreases by 23,4%, the microhardness HV and the adherence of the samples subjected to the test increases. The FeNiCrSiB-WC/TiC layers, deposited on low alloyed steel support, can be considered as convenient solutions for obtaining hard, wear-resistant surfaces.

Hard Alloys with High Content of WC and TiC—Deposited by Arc Spraying Process

“…The main disadvantages of this spraying process are related to the high porosity of the deposits (over 18%) and to carrying out deposits resistant to abrasive wear (WC, TiC) only by using high-performance equipment, equipped with command and control system, which are expensive, [31].…”

“…Chemical cleaning consisted of several steps: washing the substrate surface in a jet of liquid solution with a concentration of 10% (5% caustic soda, 5% soda salt), at a temperature of 50°C; rinsing in a stream of hot water at a temperature of 90°C; degreasing in methylene tetrachloride; wiping the substrate surface until dry with a textile material, [31]. 1.…”

Substrate Texture Influence on the Dry Sliding Wear Behaviour of Co-Based Plasma Spray Coating

“…in order to obtain a reliable coating, which successfully fulfils its role but also has durability, the substrate surface preparation stage must be strictly fulfilled [10]. this stage is very important because it has a decisive influence on the quality of the bond of the coating to the substrate surface on which it is applied [11].…”