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This article presents a study on the influence of the intensity of the welding current on the properties of the mechanical strain strength of welded joints made by using submerged arc welding technology. The influence of the welding current on the microstructure of the welded joints was also observed in different regions of the cross-section of the welding seam. Also subject to observation was the mode of influence of the welding current on the geometry and dimensions of the welding seams. The welded samples were obtained using five different welding regimes whose main variable was the intensity of the welding current, which had values between 300 A and 700 A. The criterion used as a reference for comparing the effects produced by the studied welding regimes was a standard welding regime that is used in the industry for welding railway tank wagons, with a welding current intensity of 480 A. The base material used in the experiments was a fine-grained carbon steel specially intended for the manufacture of pressure vessels identified as P355 N; the semi-finished product from which the samples were made consisted of 6 mm thick laminated sheets used in the manufacture of the covers of the vessels that make up the railway tank wagon. The aim of this study was to highlight the differences that may appear through varying the current welding parameter and identify welding regimes that can provide welded joints with superior mechanical properties compared to what is currently employed in the industry. This study focused on the most widespread technology of welding pressure vessels: the submerged electric arc welding method. [ABSTRACT FROM AUTHOR]

The steel industry is a sector where the concept of sustainable development is operationalized, and the circular economy must be implemented by recycling secondary products and transforming them into by–products used as components of natural capital. Small and powdery waste containing iron from the steel industry has a high content of useful elements that can be recovered by using them in the processing of aggregates as raw materials or auxiliary materials. To choose the optimal waste recovery technology, it is necessary to characterise it qualitatively. The purpose of the work is to present the provenance and qualitative characteristics of small and powdery industrial waste with iron content, highlighting the importance of the recovery process and the introduction of waste into the national economic circuit according to the principles of circular and green economy. [ABSTRACT FROM AUTHOR]

In the steel industry, a significant amount of waste is frequently generated, the vast majority having a high content of iron and other useful elements; for this reason, it is necessary and recommended that small and powdery industrial waste containing iron be recovered and not stored, within the same manufacturing flows where it was generated following the principles of the circular economy or, where it is not possible (due to limiting factors related to chemical composition, granulation, technological limitations, etc.), recycling is carried out in other industries (e.g. nonferrous, building materials, etc.). Their capitalization and return in the form of by-products in the steel industry or other industrial sectors produces economic and ecological effects. The work presents the possibilities of managing and characterizing some industrial waste with iron content, historically stored, and results on manufacturing flows. [ABSTRACT FROM AUTHOR]

The work presents the results obtained with regard to the tribological behavior of materials intended for the manufacture of brake blocks for motor and towed rolling stock. A composite material was developed for making clogs. On the resulting samples, determinations of wear parameters were made using the wear test installation on steel plate. In order to compare the results obtained, the tribological research was also carried out on samples of phosphorous cast iron type P10, the classic material of the brake clogs. [ABSTRACT FROM AUTHOR]

One of the most common processes using different types of zeolitic molecular sieves is the pressure-absorption PSA process, this process is used to separate a particular gas species from a gas mixture under pressure, depending on the molecular characteristics of the species and affinity for a specific adsorbent material. The paper presents a concept of using zeolitic molecular sieves in the air intake process of internal combustion engines. The concept is based on a study on the evolution of a number of parameters in the development of the various engines with which the VW Golf model was equipped in the period 1974-2004. Implementation of the concept aims to reduce the air mass flow into the engine without adversely affecting its performance. In the study were analyzed a number of factors such as the evolution of cylindrical capacities for diesel engines, evolution of the mass of the vehicle, intake air mass flow rate and the amount of fuel consumed. Analysis of the data collected shows a steady increase of the cylinder capacity which can be attributed to the request of a more powerful engine units, demand that came from the market. [ABSTRACT FROM AUTHOR]

Induction heating is a particular process which uses electromagnetic fields for heating conductive materials (steel, copper, brass, aluminium). The main difference from a traditional heating process is the location of heat sources which are distributed inside the work-piece. For this reason the induction heating process is very fast and controllable. Depending on the frequency used the heating can be superficial (induction surface hardening) or deep in the piece (forging, heat treatment etc.). The main advantages of this technology are: high production rate due to the high specific power delivered to the work-piece, high automation of the process, precise repeatability of treated pieces, in-line installation, low floor space needed, controllability of temperature with high precision, avoiding of deformation of pieces especially in surface hardening, primary energy saving, safe and clean work ambient for employees. There are a lot of applications where induction heating is used in different industries: melting of metals, heat treatments (hardening, tempering, annealing) , forging, hot rolling, surface hardening, cold crucible melting, welding, pre-heating, dry-coating, special applications. All these applications get benefits from the suitable characteristics of this technology. In this paper is presented the determination of the technological parameters for superficial hardening of axel pieces type made from 41Cr4 and 34CrMo4 steel. This technological parameters is optimum heating temperature, heating time and adequate cooling method for obtains a higher hardness. [ABSTRACT FROM AUTHOR]

Under current conditions in perspective, concern to reduce costs of raw materials and auxiliary materials, energy and fuel becomes a thing of prime importance. A detailed analysis of costs specific to each manufacturer to constitute a priority for the future existence of the steel products market. Obviously, significant reductions, it is a very important role in the modernization of equipment and technology investment. Leaving everything to the investment but would be a mistake as big as the lack of concern for finding financial resources for modernization of production flows in the performance of research for these flows. [ABSTRACT FROM AUTHOR]

In this paper we analyze the possibilities of improving the process through micropelletizing humidity and time micropeletizing mixture. Data obtained from the practice we are processed in Excel and Matlab programs to obtain technological correlations, particularly between permeability and volumetric weight of the mixture, and humidity dependent parameters considered during micropelletizing and mixing, the parameters considered independent. The correlations obtained are representative of the process and permit the establishment of range for the independent parameters, which lead to the desired value (within the limits of technology) dependent parameters. [ABSTRACT FROM AUTHOR]

In paper is presented a synthesis of results obtained of authors regarding to reinsertion in the economic circuit of scrap and pulverous waste existing in Hunedoara area. Through these capitalization of wastes in the iron and steel industry I done substantial economies in cost-price of final product, on aside, and but the other side are in progress an ecological process of environment Hunedoara area through give back of occupied surfaces with these waste to the natural frame. [ABSTRACT FROM AUTHOR]

Oxygen is one of the elements that negatively affect the quality of steel and this is the reason why, in practice, steps are being taken in order to technologically eliminate it fro,n the steel bath. The deoxidation process is influenced by several factors: temperature, the chemical composition arid state of stirring of the bath, as well as the characteristics of the slag used in the treatment (chemical structure, basic character, viscosity, specific slag quantity, kg/t). In this paper we analyzed the influence of the chemical composition and quantity of the slag and the stirring state of the bath upon the deoxidation process inside the ladle, when synthetic slag is used at a Siemens-Martin steel plant and an Electric steel plant. In order to produce the synthetic slag, we used a mixture of lime (50-75%), fluorine (0-17%), bauxite (0-32%) and aluminum slag 8-22%, produced according to several recipes, introduced at the bottom of the ladle, before tapping. We collected samples of steel respectively slag, from the jet and from the ladle, 15 minutes after the ladle was filled. The data we obtained after the analysis of the samples were processed in EXCEL and MATLAB, which led to a series of correlations between the degree of oxidation and the chemical structure of the slag respectively the quantity of slag, both for the bubbled charges and for the non-bubbled ones. The paper gives the most relevant correlations expressed both graphically and analytically, together with technological explanation. [ABSTRACT FROM AUTHOR]

Thermal metallurgical aggregates are now some of the largest energy in the national economy of any country. In this case justified the efforts made towards becoming fully aware of the possibilities of upgrading the building and optimizing their operation. Analysis of structural and functional variables of the electric arc furnace objective technical prerequisites for studying the evolution of this aggregate to increase the technology's performance. [ABSTRACT FROM AUTHOR]