Acta Technica Corviniensis

1.AMALIA ANA DASCĂLSTUDY ON THE VARIATION OF CONVENTIONALFLOW LIMIT DEPENDING ON THE MAIN ALLOYELEMENTS FOR THERMORESISTANT STEELAbstract:The paper presents the results of the research made under laboratory experimental testing, onOLT45K steel, intended to the manufacturing of tubes, used at high temperature in the make-up ofthermal-energetic installation. Mechanical driving testing has been made at the temperature of 450°C,on shares of test-bars drawn out of a number of 50 charges, with a view to achieving the optimizationof the chemical composition of this steel type. The optimization, under experimental dates, suggestsalternatives of combinations among the main elements of the chemical composition, so as the steelcan be elaborated with superior mechanical features at high temperature. The obtained results have alarge feasibility area, and can be also endorsed for other steel types and mechanical features forwhich the optimization is viewed, therefore being very useful to technologists, in the process ofachieving a certain type of steel.Keywords:high temperature, thermal resistant steel, mechanical testing, life-length, mechanical featureGENERAL APPRECIATIONGenerally, any research elaboration impliessome stages: gathering the dates, their modelingand the decisional working out. Theinformational pattern-making follows 3 steps:manual, mechanical and automatic.Its results have to be presented in a shape whichmakes them utilizable by the beneficiary, nomatter the pattern-making method.A new and important problem, raised in thestudy of multidimensional reparations, concernsthe bound among the analyzed variables andthrough them, among the phenomena theyrepresent, known as correlation. It includes twofundamental problems: the first consists indescribing the medium variation law of avariable depending on another (or other)variable(s), known as the problem of regressionand settled under the regression function, andthe irrespective of the linked variable measures.Estimating and sizing the thermal-electric powerstation pipes is extremely detailed andexpensive, regarding the use of the finiteelement programmes, as it is very hard to specifyall the testing which the pipe system is to berequested, during the estimated life length.Extreme situations and possible exploitationaccidents are also hard to estimate.This is the reason of choosing as a subject of thepaper the making of multiple correlations, IIfigure, which offers information on the influenceof two of the chemical composition elements onthe technical running limit at the temperatureguaranteed by the metal manufacturer. From thegraphical representation and knowledge of the© copyright FACULTY of ENGINEERING – HUNEDOARA, ROMANIA 31