Phosphating Depositions for Equipment’s Used in Explosive Atmospheres

According to the ATEX directive, any personal protective equipment or work equipment intended to be used in a potentially explosive area must be made of materials that cannot be the source of mechanical or static electricity-related sparks. The carbon steel is one of the most widely used metallic materials, but the possibility of using it in the manufacture of equipment used in explosive environments is low. Therefore, the purpose of this article is to present an alternative solution to use metal equipment in potentially explosive atmospheres, by depositing a phosphate layer on the surface of the carbon steel. The metal was coated by a simple process, the metal being immersed in a phosphating solution based on zinc. Due to the properties of zinc phosphate deposited on the steel surface, especially electrical insulating, the steel coated with this type of layer can be used in explosive atmosphere.

The change in the morphology of the blasted surface after phosphating and cataphoretic coating

The paper focuses on the quality of coatings applied by cataphoretic deposition and cataphoretic deposition technology with a phosphate layer. The quality of the coatings was evaluated by determining the roughness of the coatings, the morphology of the coatings, spectral analyses were performed detecting the presence of individual elements in the coatings. There was analysed also defect – uncoated spot.

Galvanic Corrosion Behaviour of Phosphate Nodular Cast Iron in Different Types of Residual Waters and Couplings

The aim of this paper is to analyze the corrosion process that occurs in galvanic couplings of different alloys. The study focuses on materials that can come into contact in submersible pumps used by water treatment plants. Because, the rotor, one of the pump main components must possess high chemical and mechanical properties, nodular cast iron is usually used. Therefore, this is exposed in the same environment with different types of materials, such as aluminum, copper, bronze, grey cast iron, low alloy steel or stainless steel from which other components are made. The tests have been performed in three types of residual waters with neutral, acidic and basic pH. According to this study, the nodular cast iron galvanic corrosion resistance is highly improved by the phosphate layer deposited on its surface. Keywords: galvanic corrosion, wastewater, nodular cast iron, phosphate layer, galvanic couple