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Quantitative assessment of the influence of plasma hardfacing parameters on the metallurgical melting of an austentic steel coating with a substrate material made of C45 steel

Bazychowska Sylwia, Starosta Robert, Dudzik Krzysztof

Journal of KONBiN

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2022

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Vol. 52, iss. 3

27--51

EN

In this paper, based on a quantitative analysis of the parameters of plasma hardfacing of C45 steel with CastoMag 45554S wire, an optimisation of the hardfacing process parameters has been carried out. Experimental researches were carried out on the basis of an orthogonal plan, and the optimum hardfacing parameters, e.g.: intensity, voltage, wire feeding speed, were determined by the multiple regression method and the Taguchi method. It was found that the main current of the plasma arc had the greatest influence on the value of the fusion index. The highest S/N value was obtained for the following parameters: I = 120 A, U = 31 V, vn = 0.75 m/min, vd = 3.9 m/min, z = 12 mm.

PL

W oparciu o ilościową analizę parametrów napawania plazmowego stali C45 drutem CastoMag 45554S dokonano optymalizacji parametrów procesu napawania. Badania realizowano na podstawie planu ortogonalnego, a optymalne parametry napawania np.: natężenie, napięcie, prędkość podawania drutu zostały wyznaczone metodą regresji wielokrotnej oraz metodą Taguchi. Ustalono, że największy wpływ na wartość współczynnika wtopienia ma natężenie prądu głównego łuku plazmowego. Największą wartość współczynnika S/N uzyskano przy parametrach: I = 120 A, U = 31 V, vn = 0,75 m/min, vd = 3,9 m/min, z = 12 mm.

2

Optimization of the process parameters of resistance spot welding of AISI 316l sheets using Taguchi method

Muthu P.

Mechanics and Mechanical Engineering

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2019

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Vol. 23, nr 1

64--69

EN

Resistance spot welding (RSW) is a fabrication process that is being used in the automobile and aerospace industry since many years for joining low carbon or “mild” steel. Quality and strength of the welds depend upon the process parameters of RSW. The most effective parameters in this process are: current intensity, welding time, sheet thickness and material, geometry of electrodes, electrode force, and current shunting. This paper presents the experimental investigations for the optimization of tensile shear stress of RSW for stainless steel grade 316L sheets by using Taguchi method. The experiments were conducted using Taguchi’s L27 orthogonal array under varying proces parameters, namely electrode diameter, welding current, and heating time. The experimental data were analyzed using signal-to-noise ratio (S/N ratio) to find the optimal process parameters. Analysis of variance (ANOVA) and F test were used to find the most significant parameters affecting the spot weld quality characteristics. Confirmation tests with optimal process parameters were conducted to validate the test results. From the results, itwas found that it is possible to increase tensile shear stress significantly.

3

Optymalizacja przetworników A/D typu Sigma-Delta dla systemów pomiarowych i akustycznych

Sidor T.

Pomiary Automatyka Robotyka

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2018

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R. 22, nr 2

17--22

PL

Przetworniki A/D są niezbędne we współczesnych systemach automatyki, wykorzystujących sterowanie komputerowe. Chociaż przetworniki typu Sigma-Delta są obecnie powszechnie stosowane w układach rejestracji cyfrowej sygnałów akustycznych, to m.in. ze względu na ich popularność mogą być również używane w systemach pomiarowych. Jednak wymagania co do jakości przetwarzania przetworników A/D są inne dla zastosowań w systemach akustycznych i pomiarowych, co wynika z diametralnie różnej dynamiki przetwarzanych sygnałów i różnych kryteriów oceny jakości. Niniejszy artykuł ma na celu przybliżenie problematyki optymalizacji struktur takich przetworników dla aplikacji w systemach akustycznych i pomiarowych.

EN

A/D converters of any type are indispensable in contemporary control systems, employing digital computers. Although converters of Sigma-Delta type are nowadays very common in systems for digital recording of acoustic signals, because they are very popular, can also be used in measurement systems. Quality requirements for both type of applications are different, as acoustic type signals and measurement signals have totally different dynamic and different criteria are used to assess converter performance in each case. This paper attempts to point out certain means used to optimize structures of such converters for acoustic and metrological applications.

4

VSP polarization angles determination: Wysin-1 processing case study

Zaręba M., Danek T.

Acta Geophysica

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2018

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Vol. 66, no. 5

1047--1062

EN

In this paper, we present an analysis of borehole seismic data processing procedures required to obtain high-quality vertical stacks and polarization angles in the case of walkaway VSP (vertical seismic profile) data gathered in challenging conditions. As polarization angles are necessary for more advanced procedures like anisotropy parameters determination, their quality is critical for proper media description. Examined Wysin-1 VSP experiment data indicated that the best results can be obtained when rotation is performed for each shot on data after de-noising and vertical stacking of un-rotated data. Additionally, we proposed a procedure of signal matching that can substantially increase data quality.

5

Optimization of turning process parameters by Taguchi-based Six Sigma

Das P. P., Gupta P., Ghadai R. K., Ramachandran M., Kalita K.

Mechanics and Mechanical Engineering

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2017

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Vol. 21, nr 3

649--656

EN

In this paper, Six Sigma approach is used for improving the quality process outputs in turning of Galvanized Iron. The objective is to optimize the turning parameters and maximize the MRR (Material Removal Rate). A L16 orthogonal array based on Taguchi experiments consisting of three controlling factors viz. spindle speed, feed rate, and depth of cut, each with four levels as required in traditional DOE setting is used here. Taguchi’s parameter design offers an approach in Design of Experiments (DOE) with control parameters optimization to attain best outcome. An orthogonal array offers a set of balanced least experiments which help in data analysis and prediction of optimum results. For each experiment, the Material Removal Rate (MRR) is calculated. The Taguchi method results in reducing the quality characteristic variation due to uncontrollable parameter through the study of response variation using the Signal to Noise (S/N) ratio by the use of Minitab 16 software. Moreover, statistical investigation shows that standard deviation and mean value of confirmation run data are reduced when compare with before Taguchi design run data was performed.

6

An experimental study on optimizing for tandem gas metal arc welding process

Lee J. P., Park M. H., Kim D. H., Jin B. J., Shim J. Y., Kang B. Y., Kim I. S.

Journal of Achievements in Materials and Manufacturing Engineering

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2015

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Vol. 68, nr 2

72--79

EN

Purpose: To enhance productivity and provide high quality production material in a GMA welding process, weld quality, productivity and cost reduction affects the number of process variables. In addition, a reliable welding process and conditions must be implemented to reduce weld structure failure. Design/methodology/approach: The research investigates the interaction between the welding parameters (welding speed, distance between electrodes, and flow rate of shielding gas) and bead geometry for predicting the weld bead geometry (bead width, bead height). Taguchi techniques are applied to bead shape to develop curve equation for predicting the optimized process parameters and quality characteristics by analysing the S/N ratio. Findings: The experimental results and measured error is within the range of 10% presenting satisfactory accuracy. The curve equation was developed in such a way that you can predict the bead geometry of constructed machinery that can be used for making tandem welding process. Research limitations/implications: In various industries the welding process mathematical model is not fully formulated for the process parameter and on the welding conditions, therefore only partial variables can be predicted. Originality/value: This paper focused on the anode-cathode distance that can prevent arc blow in tandem GMA welding process. We also analysed the welding quality characteristics according to the bead geometry and welding parameters through S/N ratio dependent on the welding speed and flow rate variation of shielding gas. Finally, a mathematical model being able to predict the welding quality based on the given welding parameters using statistical method has been developed.

7

The signal to noise ratio in the differential cryptanalysis of 9 rounds of data encryption standard

Misztal M.

Journal of Telecommunications and Information Technology

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2006

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nr 3

49-59

EN

There is presented the differential cryptanalysis method of attack on data encryption standard (DES) reduced to 9 rounds. More precise estimation than that of Biham and Shamir of the signal to noise (S/N) ratio is obtained. Also, method of using the ratio in calculation of required number of plaintexts is suggested. There are given results (time of performance) and implementation's issues of practical realisation of this attack.

8

Adaptacja częstotliwości próbkowania jako metoda kompandowania w modulacjach różnicowych

Golański R.

Kwartalnik Elektroniki i Telekomunikacji

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2001

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Vol. 47, z. 2

161-183

PL

Dokonano charakterystyki dotychczasowych osiągnięć w dziedzinie badań modulacji różnicowych z nierównomiernym próbkowaniem. Na bazie reguły maksymalizacji SQNR Abate'a wyznaczono zalezności opisujące poszczegulne parametry wyjściowe modulatora NSDM w funkcji zmian częstotliwości próbkowania. Udowodniono, że dla modulacji NSDM istnieje krok kwantyzacji ∆, przy którym, zmieniając częstotliwość próbkowania, można uzyskać minimum szumów kwantyzacyjnych zarówno przy minimalnym jak i maksymalnym poziomie mocy sygnału wejściowego. W oparciu o funkcję Lambert W wyznaczo graniczne wartości częstotliwości próbkowania, które zapewniają wymaganą dynamikę przy minimalnych szumach kwantyzacji. Przedstawiono dwa sposoby wyznaczania kroku kwantyzacji dla granicznych poziomów sygnału wejściowego. Dokonano analizy wzajemnych relacji pomiędzy parametrami wewnętrzynymi modulatora NSDM i przedstawiono je w postaci graficznej. Zależności te pozwalają na ustalenie logicznego sposobu postępowania podczas doboru parametrów modulatorów z adaptacją częstotliwości próbkowania. Zaprezentowano kilka przykładowych diagramów wskazujacych na poprawną kolejność i sposób doboru parametrów modulatorów różnicowych ze zmienną szybkością próbkowania.

EN

Fundamental works of Hawkes, Un, Zhu and Abate, are shortly presented. Some results in the paper are based upon previously obtained formulas for DM and ADM delta modulators. The staircase in the delta modulation system can be adapted to the amplitude variations of a input signal by varying sampling frequency (Nonuniform Sampling Delta Modulation method). In the article signal to noise formula for NSDM modulator having a random inputs is shown. The calculation method of the minimum (fpmin) and maximum (fpmax) sampling frequency based on changing of the slope overload factor is presented in this paper. Design of the parameters (fpmin' fpmax and quantization step size ∆) for NSDM delta modulator is derived. Formula of maximization SQNR for different power levels of the input signal by means of various sampling frequency in the NSDM modulation is the main effect of discussion. The paper presents analytical and graphical dependences between the most important parameters of the NSDM. These dependences help to establish a method of procedure during the choice of the parameters of the NSDM modulator. This relationships could be the base to design of a non-uniform sampling modulators. Some example of design of the parameters is presented.