WORK SAFETY SELF-ASSESSMENT. APPLICATION, WORK LOAD

The occupational safety self-assessment system for small and medium-sized enterprises (SMEs) is a powerful tool, through which SMEs or departments of a large enterprise can decide where and how occupational safety and health activity should be improved through concrete proposals and prioritization. In the paper we deal with the self-assessment of the independent component of the work system, namely the work load, at the Metal Casting Laboratory within the Faculty of Materials Science and Engineering of the "Gheorghe Asachi" Technical University in Iași. The aim is both to achieve the qualitative assessment through the Weaknesses - Strengths table, as well as to achieve the quantitative assessment by obtaining that Score that leads us to a qualification corresponding to the value of the score. These evaluations, qualitative and quantitative, lead us to adopt measures to improve or maintain work security at a level close to the level of safety for which the company or department was designed

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

Obtained by different spraying technologies: in atmospheric plasma spray, High Velocity Oxygen Fuel (HVOF) or laser cladding, the layers of hard alloys with a high content of WC and TiC find their industrial applications due to their high hardness and resistance to wear. Recognized as being a process associated with welding, the arc spraying process is a method applied industrially both in obtaining new surfaces and for reconditioning worn ones. This chapter presents the technology for obtaining ultra-hard layers based on WC and TiC - by the arc spraying process, using a classic spray device equipped with a conical nozzle system and tubular wire additional material containing ultra-hard compounds (WC, TiC). To study both the quality of deposits and the influence of thermal spray process parameters on the properties of deposits with WC and TiC content, we approached various investigative techniques, such as optical scanning microscopy (SEM), X-ray diffraction, and determination of adhesion, porosity, Vickers micro-hardness and wear resistance

Immersion Behavior of Carbon Steel, Phosphate Carbon Steel and Phosphate and Painted Carbon Steel in Saltwater

The carbon steel is used in many areas due to its good mechanical properties; however, its low corrosion resistance presents a very important problem, for example, when carbon steel carabiners are used in the petroleum industry or navy, the possibility of an accident is higher due to carabiner failure. This phenomenon could occur as a consequence of the corrosion process which negatively affects mechanical properties. This paper study the possibility to improve its corrosion resistance by depositing on its surface a phosphate layer and a paint layer, and also aims to analyze the immersion behavior in saltwater of carbon steel, phosphate carbon steel, and phosphate and painted carbon steel. According to this study, by coating the carbon steel with a phosphate or paint layer, a higher polarization resistance is obtained in saltwater. Moreover, by electrochemical impedance spectroscopy (EIS), it was observed that the corrosion rate decreases with the increase of the immersion time. Meanwhile scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) revealed that the main compounds which formed on the sample’s surface were iron oxides or hydroxy-oxides, after immersion for a longer period. The overall results show that all types of deposited layers increase the corrosion resistance of C45 steel

Comparative Rolling Contact Behavior of Two APS Coatings with Different Matrix

In this study we analyzed the rolling contact fatigue behavior of two types of coatings made by thermal coating, by the method of atmospheric plasma spraying (APS) from two commercially available powders: Ni5Al5Mo and Al2O3 - 13 TiO2. The contact fatigue behavior was studied on an installation specially designed. The specimens were tested for 54 hours (at 1380 rpm), at a load of 944 N. For both types of coatings, the appearance of a wear path was observed, much more obvious in the case of the Ni matrix layer, also confirmed by profilometry. The mechanism of the wear phenomenon was predominantly of plastic deformation type (the material was pushed towards the edges of the wear path) in the case of NiAlMo coating. In the case of ceramic coating, the wear path width was very small (300-450 μm), with very few changes at the surface level of the coating, which recommends this type of material for applications that require wear resistance to rolling

CORROSION AND WEAR OF WASTEWATER PUMPING SYSTEMS

The submersible pumps are submerged in the fluid that must be pumped, this type of pump is capable to push out large volumes of water. The watertight subassembly of this equipment includes a variable power engine that can be used for various household applications or industrial purposes. Wastewater transported by pumps corrodes and wear the transport system. The materials used for the construction of these pumps must withstand the acidity of the water, capitation phenomenon, the wear caused by the particles in the suspension and maintain their operating properties. The paper presents an analysis of the wear and corrosioneffects on the wastewater pumps and an analysis of the pump impeller material

The influence of economic factors in the management of health and safety specific to SMEs

The first of the general objectives of the National Strategy in the field of health and safety at work for the period 2018 - 2020 in Romania was “a better implementation of the choice of occupational safety and health legislation, especially in micro-enterprises and SMEs”.In this context, this paper presents the main vulnerabilities of management in SMEs, where the occupational safety and health component has a formal role being strongly influenced by economic factors. The first part presents a statistical situation of the verification campaigns, carried out in the last 3 years by Labor Inspection, on how SMEs have implemented health and safety legislation in their activities, subsequently, an analysis is made of the economic factors that have limited the development of health and safety management. Finally, a cost-benefit analysis is presented on the economic consequences that occur in the event of an accident and / or illness that demonstrates the theory that economic factors influence the management of health and safety and health specific to SMEs both before and after an event occurs

Corrosion Behaviour of Nodular Cast Iron Used for Rotor Manufacturing in Different Wastewaters

Submersible drainage sump pumps work in a highly corrosive environment, forming films with corrosive reaction products on the surface. Pump rotors are high-demand parts, so they are made of quality materials with good wear and corrosion resistance properties such as nodular graphite cast iron. This paper analyses the corrosion behaviour of cast iron used in the manufacture of rotors in three types of wastewaters, with variable pH. Nodular graphite cast iron samples were immersed in wastewater for 30, 60, and 90 days and tested by linear polarisation and electrochemical impedance spectroscopy (EIS). Also, the layers of reaction products formed on the surface of the material were analysed by SEM and EDS. The results showed that nodular cast-iron immersed in wastewater with acidic pH showed intense corrosion, the oxide layer formed on its surface is unstable. Also, the final structure of the product layer is that of a tri-layer with cations and anions absorbed from the corrosion media: the double-electric layer directly connected to the metal surface, an internal layer consisting of ferrous compounds and ferric compounds that control the diffusion of oxygen, an outer layer, and a compact crust of ferric compounds. The change in the pH of the wastewater has a major influence on the corrosion rate of the cast iron, which increases from 356.4 µm/year in DWW-1 (6.5 pH) to 1440 µm/year in DWW-2 (3 pH) and 1743 µm/year DWWW-3 (11 pH) respectively. As can be seen, the experimental study covers the problem of the corrosion behaviour of the pump rotor in various types of wastewaters this aspect is particularly important for the good use of wastewater pumps and to predict possible deviations for the operation of the equipment within the treatment plants

Obtaining and Analysis of a New Aluminium Bronze Material Using Induction Furnace

Copper-based alloys with the addition of Al present excellent properties and can be considered a proper choice for applications as contact materials based on their good strength and fret resistance. Cu-Al alloys are used in different systems parts as bearings, gears and worm gears. The intention is to replace steel materials with new copper-based materials for parts that work in a possible explosive environment to reduce the possibility of spark appearance. Copper-berilyum alloys are known as non-sparking alloys and are used in different tools obtaining for environments with possible explosive gaseous. Results from the obtaining and analysis of a new alloy based on CuAlBe are given. The material was melted in a vacuum induction furnace from CuBe master alloy and high purity aluminium and cast into a metallic die. The alloys obtained were analyzed using EDS - energy dispersive spectroscopy for chemical composition, OM-optical and SEM-electronic microscopy for the microstructure, and the electro-corrosion resistance was tested using linear Tafel diagram and cyclic potentiometry

Carbon steel carabiners improvements for use in potentially explosive atmospheres

In cases where an explosive atmosphere contains several types of inflammable and/or combustible gases, steams or powders, the protection measures must be appropriate to the highest possible danger. However, the employer must pay special attention to the workplace and to any factor that can influence the working conditions, especially to those related to the workers. Therefore, any device, tool or equipment used by the human operator must possess special properties. In addition to protective clothing, workers who work at heights must receive personal protective equipment against falling that includes multiple linking elements known as carabiners. The carabiners used in this equipment must be made of non-sparking material. The aim of this paper is to propose a spark characteristic improvement of carbon steel used in carabiners manufacturing by deposition of zinc phosphate coating