The article presents a calculation model of the linear energy of welding P235GH steel tubes with ... more The article presents a calculation model of the linear energy of welding P235GH steel tubes with high-frequency currents in order to obtain an optimal microstructure and geometry of the weld of high internal purity. The model was developed based on real data for the standard linear energy used in the steelworks Huta Łabędy and presented as the power factor P/V and P/(V·t), where P is the power [kW], V the production speed [m/min] and t the wall thickness. The model can be used for two ranges of pipe diameters: 114.3–168.3 mm and 219.1–323.9 mm. The data from the model were implemented into the High Frequency Induction (HFI) control panel of Huta Łabędy in order to produce test tubes which were subsequently tested with ultrasounds to verify the quality of the internal weld. In addition, samples were taken for metallographic analysis, which was supposed to check whether the applied linear energy calculation model allows the obtainment of the optimal weld geometry and the optimal angle...
The processes of rolling and annealing of explosively welded multi-layered plates significantly a... more The processes of rolling and annealing of explosively welded multi-layered plates significantly affect the functional properties of the composite. In current research, fifteen-layered composite plates were fabricated using a single-shot explosive welding technique. The composites were then rolled up to 72% to reduce layer thickness, followed by annealing at 625 °C for varying times up to 100 h. Microstructure evolution and chemical composition changes were investigated using scanning electron microscopy equipped with energy-dispersive spectroscopy. The mechanical properties of the composite were evaluated by tensile testing, while the strengths of individual layers near the interface were evaluated by micro-hardness measurements. After explosive welding, the wavy interfaces were always formed between the top layers of the composite and the wave parameters decreasing as the bottom layers approach. Due to the rolling process, the thickness of Ti and Al layers decreases, and the wavine...
This paper presents the results of numerical tests of the process of forging magnesium alloy ingo... more This paper presents the results of numerical tests of the process of forging magnesium alloy ingots (AZ91) on a hydraulic press with the use of flat and proprietary shaped anvils. The analysis of the hydrostatic pressure distribution and the deformation intensity was carried out. It is one of the elements used for determining the assumptions for the technology of forging to obtain a semi-finished product from the AZ91 alloy with good strength properties. The aim of the research was to reduce the number of forging passes, which will shorten the operation time and reduce the product manufacturing costs. Numerical tests of the AZ91 magnesium alloy were carried out using commercial Forge®NxT software.
This paper presents the results of research on the determination of the influence of kinetic asym... more This paper presents the results of research on the determination of the influence of kinetic asymmetry of work rolls on structural changes in hot-rolled bimetallic sheet metals. The tests were conducted on bimetallic samples composed of materials 10CrMo9-10 + X2CrNiMo17-12-2. The scope of the research included a comparative analysis for two cooling variants: I in water (freezing the structure immediately after rolling) and II for cooling in air. The research conducted showed that the introduction of asymmetric conditions to the rolling process results in a greater grain fragmentation in the so-called hard layer and does not have a negative effect on microstructural changes in the soft layer.
In the work the results of plate rolling process of the experimental steel designed for plate whi... more In the work the results of plate rolling process of the experimental steel designed for plate which meets the requirements for grade X80÷X100 according to API5L were presented. The simulations were carried out using laboratory stand mill duo 300. The aim of the experiment were a verificaton of rolling conditions determined based on physical and numerical simmulations. The structure and mechanical properties of plates after thermo – mechanical treatment were determined.
M. Knapinski, A. Kawalek, B. Koczurkiewicz, T. Garstka, Faculty of Production Engineering and Mat... more M. Knapinski, A. Kawalek, B. Koczurkiewicz, T. Garstka, Faculty of Production Engineering and Materials Technology, Czestochowa University of Technology, Czestochowa, Poland The research presented in the current paper was carried out for the experimental steel designed for plate which meets the requirements for grade X100 according to API5L. The tested steel is fine-grained constructional steel for making tubes for gas pipelines with minimal yield point of 690 MPa and tensile strength over 760 MPa. The laboratory tests were obtained that in the structure the polygonal ferrite were observed. That may have a disadvantageous influence on the limit of plasticity value X100 steel. The corrections of the chemical composition were carried out. The temperature and deformation schemes in the thermo-plastic treatment phase were determined.
The paper presents the results of numerical modelling of the forging process of magnesium alloy i... more The paper presents the results of numerical modelling of the forging process of magnesium alloy ingots on a hydraulic press with the use of flat and shaped anvils. The use of shaped (rhombic-trapezoid) anvils will affect the uniform distribution of temperature and strain intensity in the entire volume of the forging, causing a number of forging passes, which in consequence will reduce the costs of the blank manufacturing process. However, higher values of the strain intensity were obtained during the deformation of the material in flat anvils. The purpose of the research was to propose assumptions for forging technology of producing a blank from AZ91 alloy with the use of flat and shaped anvils. Numerical examination for AZ91 magnesium alloy was carried out using the Forge®NxT commercial software. The rheological properties of the investigated alloy were determined on the basis of uniaxial compression tests carried out in the Gleeble 3800 metallurgical simulation system. The numeric...
Intracranial haemorrhage in the course of ischaemic stroke in patients receiving IV thrombolytic ... more Intracranial haemorrhage in the course of ischaemic stroke in patients receiving IV thrombolytic therapy-a study of 141 patients from Gliwice and its vicinity. An attempt to determine risk factors based on authors' own experience Krwotok śródczaszkowy w przebiegu udaru niedokrwiennego mózgu u chorych leczonych trombolitycznie i.v. w populacji z Gliwic i okolic-analiza 141 przypadków. Próba określenia czynników ryzyka na podstawie materiału własnego
[The influence of radiotherapy of head and neck cancers on carotid arteries]
Przegla̧d lekarski, 2014
Modern radiotherapy of head and neck cancers involves high dosage of radiation per tissue volume ... more Modern radiotherapy of head and neck cancers involves high dosage of radiation per tissue volume including carotid arteries. Little is known about the mechanism of influence of radiotherapy to the large carotid arteries it may lead to inflammatory condition in the vascular wall, intima-media thickness (IMT) of the vessel and increase atherosclerosis. This work is based on current knowledge and presents the results of research which is based on ultrasound assessment of IMT and atheromatous changes in the carotid artery in a group of 61 irradiated patients with head and neck tumors. To assess IMT, the progression of the atheromatous changes in the carotid arteries of patients who had completed radiotherapy in comparison with a control group of non-treated patients and to determine the relation between the progression of the atheromatous changes, the radiation dosage and time after their radiotherapy. The ultrasound tested carotid arteries of 61 patients. The mean of the dose in the ca...
The Study of Heat Transfer Coefficient during Cooling Plates of High Strength
Solid State Phenomena, 2015
Nowadays methods of hot-rolled sheets should ensure high mechanical and plastic properties of she... more Nowadays methods of hot-rolled sheets should ensure high mechanical and plastic properties of sheets, in-line rolling. Such technologies require application of devices for accelerated cooling of a band after last deformation. The essential thing in this process is selection of an appropriate positioning of the cooling intensity. The paper presents results of the cooling intensity for the selected air-water nozzle. On the basis of the results, the map of distribution of heat transfer coefficient for the nozzle to the surface of the cooling was performed. These tests were carried out for different settings of water and air. The research was carried out for high-strength steel. The obtained results allow executing of computer simulation of the impact of cooling intensity on the final product’s structure.
Analysis of Barkhausen noise in explosively cladded titanium-nickel bimetallic plate was studied ... more Analysis of Barkhausen noise in explosively cladded titanium-nickel bimetallic plate was studied to test feasibility of using this magnetic nondestructive technique for evaluation of its properties as stress or strain state. The research on the influence of applied strain on Barkhausen Noise (BN) in nickel layer was carried out, and the impact of magnetization frequency on BN envelope was investigated too. Finally, the radial plots of BN intensity correspond to stress state were determined. Obtained results let to conclude that BN analysis method can be additional reliable testing tool for Ti-Ni plates characterization.
In this paper the integrated construction of HMI interface, dedicated to cooperation with program... more In this paper the integrated construction of HMI interface, dedicated to cooperation with programmable logic controller was presented. Modular structure of interface, installed inside casing for mounting on DIN rail, allows installing it in standard control cabinets along with other automation components. Operation of PLC’s subroutine for cooperation with presented interface as well as results of its investigations during practical tests was shown. (EMG interface for PLC controller) Słowa kluczowe: Sygnał elektromiograficzny, interfejs, sterownik PLC.
The article describes the set gap mill DUO-300 forms part of the rolling of the Faculty of Produc... more The article describes the set gap mill DUO-300 forms part of the rolling of the Faculty of Production Engineering and Materials Technology of Czestochowa University of Technology. Control of technological line based on controllers PLC. For communication between the individual elements used data bus CANBus. The paper describes in detail the algorithm set the upper roller mill. Automatic control according to the algorithm presented primarily allowed to shorten the time and increase the precision of the set of rollers which was impossible to obtain the original, manually controlled system.
The article presents a description of the automatic level control roller tables given-receiving m... more The article presents a description of the automatic level control roller tables given-receiving mill DUO-300 forms part of the rolling of the Faculty of Production Engineering and Materials Technology of Czestochowa University of Technology. Control of technological line based on PLC. For communication between the individual elements used bus CANBus. Realized an automatic level control roller tables rolling laboratory DUO-300, despite the relative simplicity associated with the lack of proportional valves and the resulting inability of proportional control, allows you to achieve satisfactory accuracy parameters and time settings.
The paper presents preliminary tests of high carbon steel wire rods by the non-destructive Barkha... more The paper presents preliminary tests of high carbon steel wire rods by the non-destructive Barkhausen method. Correlation between applied external stress to the wire rod and current sweep characteristics were observed. Some geometrical parameters of the shape of these characteristics corresponded to mechanical stress state were assigned. Obtained result can be used for more reliable estimation of residual stress state and quick comparison of residual stress level in wire rod after different production variants. Streszczenie. W artykule zaprezentowano wstępne badania walcówki ze stali wysokowęglowej za pomocą nieniszczącej metody Barkhausena. Zaobserwowano korelację pomiędzy zadawanymi w walcówce naprężeniami a charakterystykami typu sweep. Pewne parametry geometryczne kształtu tych charakterystyk, korespondujące ze stanem naprężeń mechanicznych, zostały wyznaczone. Uzyskane rezultaty mogą być pomocne dla bardziej wiarygodnej oceny stanu naprężeń własnych i szybkiego porównywania ich poziomów w walcówce po różnych wariantach produkcji (Próba oceny stanu naprężeń w walcówce zestali wysokowęglowej C68D za pomocą metody Barkhausena).
Uploads
Papers by Tomasz Garstka