Structural modifications which appear in the area of welds of welded structures made of ST 52.3 steel

Using metal construction made of St 52.3 steel is very large and in these conditions an area of interest to use them is represented by the equipments which work in difficult conditions. Due to the heavy conditions of such welded structures, and also the working environment action on these welded structures, in practice it is necessary to know any structural modification that is produced in both the base material and the filler material. Research has followed in the main the analyze of structural modifications of the materials in the area of welded joints by corner, and also in the heat affected zone

Research on deformations which appear in within the metal structures of mining equipment

Metal structures of the mining equipment are made of a steel with good weldability and mechanical characteristics corresponding and namely St 52.3 steel that allows the use of these metal structures in heavy duty. Metal structures of the mining equipment are very large structures and strong requested mechanical, and in these conditions during exploitation can occur large deformations at these that may cause a decrease in the exploitation safety of mining equipment. Research has followed in principal the analyze of deformations appear in metallic structures, and for realizing the researches has been used both a dimensional analysis and one that is based on the finite element method

Influence of parameters of welding regime on metallographic structure of materials from a joint welded in corner in „T” form

To achieve metal constructions with high importance, it can be used different steels, but steel OL 52.4k has a very wide use due to technological properties and mechanical they present. Metallographic structure of materials of a welded joint is influenced by conditions that occur in the process of welding. In the researches there have been studied the influence of parameters of welding regime on the system of metallographic structure of materials from a welded joint in corner in “T” form. There was taken into account welding process MAG using three welding regimes and using steel plates from OL 52.4k steel with a thickness of 10 / mm

Risk estimation of air pollution produced by a welded constructions company

The study refers to the air pollution produced by a welded constructions company that achieves a production of 1000 t of products/month. Air quality monitoring was conducted in the area of infl uence of the welded construction company that is 200 m radius around the company and the monitoring period was May to September, 2008-2011. Air quality monitoring was performed in seven different monitoring stations denoted by A, B, C, D, E, F, G. For air quality monitoring we have measured the concentrations of various pollutants (NH3, NO2, SO2, CO, H2CO, HCl, phenols), and for each hazard the hazard ratio was calculated

Researches on the chemical composition and hardness modifications that appear in the material of tools used for rubber waste attrition

This paper presents the results of the main changes in the chemical composition of the material, and changes in its hardness. The changes in terms of chemical composition refer primarily to changes in concentration of sulfur and carbon, and in terms of hardness material change there can be noticed a decrease in hardness of the material that is in direct contact with waste rubber

Researches regarding structural modifications that appears in the material of tools used for rubber waste attrition

Tools commonly used for shredding rubber waste, currently produced, are made of neatly cast iron in the composite is to avoid the presence of sulfur and phosphorus. In this paper are presented the main structural material changes that occur in different areas, located at different distances from the active surface of tools. Structural changes occurred mainly refers to the transformation of white iron surface layer to gray cast iron and graphite separations appearance, which causes the crack primers and cracking corrosion phenomena in tools material

Researches on the chemical composition and hardness modifications that appear in the material of tools used for rubber waste attrition

This paper presents the results of the main changes in the chemical composition of the material, and changes in its hardness. The changes in terms of chemical composition refer primarily to changes in concentration of sulfur and carbon, and in terms of hardness material change there can be noticed a decrease in hardness of the material that is in direct contact with waste rubber

Analysis of metallographic structure and hardness of aluminum alloy 3L59 from the structure of vulcanization equipment

The use of aluminum and special alloys of aluminum in the construction of large installations as is the case of vulcanization equipment, cause a substantial reduction in their weight, while increasing the useful capacity used in the joint process. Metallic structure of vulcanization equipment is made of aluminum alloy 3L59, and after a period of use it was found a deterioration of the quality of joints caused by the modification of the properties of the metallic structure from 3L59. The modification of the properties of the metallic structure is determined by the presence of heat in the vulcanization process and in this regard it has been made an analyze of modifications of metallographic structure and hardness which occur in aluminum alloy 3L59

Analysis of metallographic structure and hardness of aluminum alloy 3L59 from the structure of vulcanization equipment

The use of aluminum and special alloys of aluminum in the construction of large installations as is the case of vulcanization equipment, cause a substantial reduction in their weight, while increasing the useful capacity used in the joint process. Metallic structure of vulcanization equipment is made of aluminum alloy 3L59, and after a period of use it was found a deterioration of the quality of joints caused by the modification of the properties of the metallic structure from 3L59. The modification of the properties of the metallic structure is determined by the presence of heat in the vulcanization process and in this regard it has been made an analyze of modifications of metallographic structure and hardness which occur in aluminum alloy 3L59

Characteristics and tendencies in the steel industry, globally and regionally

The objective of this paper is to highlight the current state of the steel industry at the global and regional level, in terms of its level of important indicators, such as: production capacity, production volume, level of consumption, exports and imports. The data used are systemized on time intervals, resulting in that the steel industry remains an attractive sector for investors in terms of large profits generated, but extremely sensitive to economic fluctuations and measures taken by the authorities. In this regard, the disparities and trends of the analyzed periods at global and regional level highlight the different ways of managing the situation in the steel sector, overcapacity representing a highly controversial element nowadays