The development of theory and practice related to the asymmetric longitudinal rolling process is based on the general theory of metalworking by pressure and symmetric rolling theory, to which a large number of scientists brought their contribution. The rolling of metal materials was a serious problem throughout history, either economically or technically, because the plating technologies enabled the consumption of raw materials (scarce and expensive) to be reduced, while improving the mechanical properties. Knowing the force parameters related to asymmetric rolling leads to the optimization of energy and raw material consumption. This paper presents data on symmetric rolling process, in order to comparatively highlight the particularities of the asymmetric process.

The paper presents a comparative analysis between experimental results and modelling in order to interpret the value of the contact pressure on the asymmetric longitudinal rolling. It is also intended action and the different behaviour of upper cylinder compared to the lower cylinder action in situations when both are driven, or only one operates. In the modelling will be presented on the basis of boundary conditions imposed rolling pressure variation in the degree of reduction and also re size arc length of contact. Determining a curve is also important to determine the locus of points which characterize symmetry conditions partial rolling process between unequal diameters cylinders.

The eight disciplines (8D – Eight Disciplines of Problem Solving) model is a problem solving approach typically employed by quality engineers or other professionals and commonly used by the automotive industry. It is a meticulous process used to solve complex problems and its purpose is to identify, correct, and eliminate recurring problems, and it is useful in product and process improvement. The 8D is a method of analysis that after the detection of an irregularity, identifies and seeks the methods of solving and preventing nonconformity. It is a highly disciplined and effective scientific approach for resolving recurring problems and provides excellent guidelines to identify the root cause of the problem, implement containment actions, develop and then implement corrective actions and preventive actions that make the problem go away permanently. Therefore, the Eight Disciplines of Problem Solving (8D) is a problem-solving tool used usually in response to the removal parameters or known product specifications set by customers and incorporates all the important aspects of problem solving: problem description, root cause analysis, correcting the problem and preventing the problem. The approach establishes a permanent corrective action based on statistical analysis of the problem and focuses on the origin of the problem by determining its root causes. Although it originally comprised eight stages, or disciplines, it was later augmented by an initial planning stage. The 8D method application will result in improved products and processes is structured into eight disciplines, focusing on the synergy of the team. This is a popular method for problem solving because it is reasonably easy to teach and effective.

Asymmetric rolling is a technique used to control both the texture and the grain refinement of metallic materials. The aim of asymmetric rolling is to apply a large shear strain uniformly through the thickness of the plate, by maintaining a high degree of friction between the sheet and the rolls. It can be used to improve the formability of material. One of the advantages of asymmetrical rolling is that the rolling force and torque can be decreased. An economic and technological reason, in particular the longitudinally asymmetric rolling is very important to determine the optimum process parameters. The paper presents a method of simulating the asymmetric rolling process. This simulation is carried out to establish the main parameters of rolling particular asymmetric regime. The main goal is to establish a link between the peripheral speed of rolls, pressure and contact length.

Using Fluid Dynamics Analysis (CFD) provides the opportunity to achieve a faster and more thorough study of fluid flow processes and is an important step to obtain information that cannot be obtained otherwise. The finite element method is generally more accurate than the finite volume method, but finite volume method can achieve more accurate mass balances using the balance sheet continuity per volume control. Finite volume method is more appropriate when fluid transport, while the finite element method is used more in the calculations of tension or conduction, which satisfies local continuity condition, is of less importance. Fluid Dynamics Analysis (CFD) is used in numerical analyzes, based on a set of mathematical expressions on linear complex equations defining fundamental fluid flow and heat transfer. This paper presents the simulation of air flow through a tube of special construction in interpreting the law of Bernoulli energy. Laboratory systems are shown, respectively simulating the actual fluid flow.

The steel's deformation resistance, in which high strain rates have an important influence on the mechanism of failure, might be obtained from a suitably instrumented torsion test. Determination of stainless steel deformability by hot torsion test is the only method that allows obtaining large deformations along the length of the test specimen, so it is mainly used to determine the characteristics at large plastic deformations. By this method, the hot deformability of stainless steel is determined by subjecting to hot torsion the cylindrical stainless steel specimens maintained at the deformation temperature in a tubular oven belonging to the Laboratory of Metal Rolling and Plastic Deformation, at the Faculty of Engineering - Hunedoara, University Politehnica Timisoara. For the experimental hot torsion tests, several stainless steel grades were used and included in a large series of studies destined to determining the deformation behavior of steel. Having in view the previous results obtained in the study of deformability characteristics of two stainless steels (hardenable martensitic stainless steel, grade X46Cr13 and non-hardenable ferritic stainless steel, grade X6Cr17), this paper includes the results of the hot torsion tests conducted to find the deformation behavior of the non-hardenable austenitic stainless steel (grade X5CrNi18-10). For analysis of laboratory hot torsion tests results the univariate and multivariate regression analysis was used, estimating the relationships among the hot-testing temperature, torque moment and number of torsions up to the breaking point of the specimens of austenitic stainless steel. Therefore, the optimum range of heating temperatures applied for deforming the studied steels results clearly from the deformability - temperature (plasticity - temperature and deformation resistance - temperature) diagrams. Correlations are useful because they can indicate a predictive relationship that can be exploited in the laboratory or industrial practice.