Considerations Regarding the Evolution of the Steel Thermal State in the Continuous Casting Plant

In continuous casting it is very important that the cooling system is correctly dimensioned. Improper cooling conditions can reduce the quality of the finished product and cause perforations of the solidified crust. In order to be able to minimize the occurrence of defects, it is preferable that, under the conditions of a given cooling system, the temperature distribution in the steel wire be known. It is also necessary to know the thickness of the solidified crust, especially immediately below the crystallizer, because a thin crust at this level can be perforated due to the ferrostatic pressure of the steel. The knowledge of the thermal state of the steel in the continuous casting installation is necessary for the transposition on mathematical bases of the technological process and the elaboration of some models of simulation of the solidification, which would allow to optimize the operation of the afferent installations. By considering the convection motion can be explained the influence of electromagnetic agitation and deformation of the steel wire on the incompletely solidified area on the quality and structure of cast steels; convective currents reduce overheating, which leads to a decrease in columnar crystallization in favour of axial crystallization. By running the simulation program were determined the variation of the thermal flux at different levels in the tundish, as well as the evolution of the temperature at the surface of the continuously cast steel thread

Determination of the Grinding Roller Grinding Arrow in a LBC Finisher

The required profile of the cylinders is achieved by their proper correction after the change due to wear. In this paper I studied how the profile of the working cylinders can influence the profile of hot rolled steel strip

Considerations Regarding the Evolution of the Solidified Crust at the Continuous Casting Steel

The continuous casting of the steel can cause cracks on the surface or inside, which arise due to thermal and mechanical stresses. To eliminate these defects, mathematical models are drawn up with which temperature fields, expansions and stresses can be determined. The purpose of making these models is to locate the areas with a high risk of cracking so that, finally, the continuous casting machines and working conditions can be modified, so as to eliminate, or at least diminish, the defects. The knowledge of the thermal state of the steel in the continuous casting machine is necessary for the transposition on mathematical bases of the technological process and the elaboration of some simulation models of the solidification, which would allow the optimization of the afferent plant. The proposed mathematical model takes into account - when studying the heat transfer phenomena in the tundish - the convective motion of the steel, which influences the thickness of the solidified crust and the evolution of the temperature in the section of the continuously cast steel thread. By running the simulation program were determined the variation of the thickness of the solidified crust as a function of time, overheating in the crystallizer and convection coefficient

Experiments Regarding the Fabrication of the Higher Strength Steels Plates

The normalizing of ferritic-pearlitic steels is a heat treatment, which consist of reheating into the austenite and subsequent air-cooling. For greater thickness, e.g. 100 mm, variations in the requirements may be permitted or required for particular applications but a reduction of the required impact energy is not allowed. The most important cote of the cost can be eliminated if the process normalizing rolling is applied

The Analysis of a Workplace From an Ergonomically Criterion. Case Study: Preliminary Charge

This paper presents a practical method of analyzing a wokplace from an ergonomically criterion based on an "ergonomic analysis questionnaire", and, also, the conclusions and proposed measures in order to improve the activity of the analyzed workplace

Optimization Techniques for the Neutralization of the Polluted Waters from Metal Plating

The problems related to the protection of the environment are regarded especially as a result of the local pollution by the industry and agriculture or by the overcrowded areas, which have led to the disturbance of some ecosystems and to worse living conditions of people. The extensive use of chemical substances in the technological processes demands special measures concerning the protection of the environment. A major problem is the purification of industrial waste water

The Value of the Strucutral Remanence and Thermic Tensions in the Forged Pieces

The plastic deformation, the heating and the cooling of the pieces submitted to plastic deformations acumulate remanent tensions inside the pieces. Knowing the environmental where they are produced and avoiding its superposition in an important problem for a specialist who aims to get through the forging process some pieces dimentionally corresponding and without defects. This works will analyse the value of the structural remanent and thermal tensions in the case of some forged pieces

R.N.U.R. Method of Risk Assessment Based on Ergonomic Criteria. Case Study: Crane Maintenance Electrician

This paper presents a case study on the evaluation of a job (electrical maintenance) in AMG plant through a less used method in Romania, respectively Renault method, used especially in France. Means of work are analyzed on the basis of the technological equipment, the work task based on the job description and the work medium based on analyzes of made by occupational medicine. The test results are tabulated and graphically processed and they are taking into account to establish the conclusions and the measures to be imposed at the analyzed work place

Research on Corrosion Resistance of Steel Plates for Shipbuilding

The corrosion of metallic materials is their partial or total destruction through chemical, electrochemical or biochemical reactions, by spontaneous interaction between the surface and the corrosive medium pollution. Generally, corrosion is defined as a medium attack to a material, an attack that leads to a worsening of the properties or destruction. Corrosion is not limited to the destruction of metallic materials; it affects equally plastics, ceramics, concrete and even the environment with which they interact

Improving Functional Parameters for Pressure Casting Machine with High Degree of Finishing

The paper presents a mathematic model of static and dynamic characteristics for casting machine. This machine has a hydraulic action for the casting chamber (her closing and introducing of molten alloy). This action is made by use an axial piston pump with the variable cylinder with pressure regulator. The mathematic model of how the injection pump functions (for molten alloy) can do by a computer simulation. This kind of approach for the study problem leads to the identification of key parameter and malfunction of these hydraulic parts. The malfunction simulation for the important work parameters (hydraulic force necessary to push the molten alloy in the shell, pressure compensated flow controls the strength to close the two rooms where the molten alloy is sent) show permanently the operator the place where a damage is produce and it is necessary his intervention