Wyniki wyszukiwania - BazTech

1

New possibilities to synthesize oligoetherols with azacyclic rings

Cyzio K., Lubczak J.

Polimery

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2011

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T. 56, nr 11-12

856-860

EN

A new method of preparation of oligoetherols containing azacyclic rings from isocyanuric acid (IA), uric acid (UA) or melamine (MEL) with an excess of glycidol (GL) and oxiranes without using solvent is presented. The method can be extended on synthesis of oligoetherols with other azacyclic compounds containing amine, amide or imide groups.

PL

Dotychczasowe sposoby syntezy oligoeteroli z pierścieniami azacyklicznymi polegają najczęściej na reakcjach melaminy (MEL) lub kwasu izocyjanurowego z oksiranami. Wadą tego sposobu syntezy jest brak dobrych rozpuszczalników melaminy i kwasu izocyjanurowego, w których można by prowadzić reakcje z oksiranami, bowiem wspomniane związki heterocykliczne rozpuszczają się tylko w DMSO i DMF ale dość słabo. Po zakończeniu reakcji istnieje konieczność oddestylowania toksycznych i wysokowrzących rozpuszczalników. W pracy zaproponowano nową, bezrozpuszczalnikową metodę otrzymywania oligoeteroli z pierścieniami azacyklicznymi w reakcjach kwasu izocyjanurowego (IA), moczowego (UA) lub melaminy (MEL) z glicydolem (GL), a następnie z oksiranem, takim jak tlenek etylenu (EO) lub tlenek propylenu (PO). Wskazano możliwości rozszerzenia tej metody na syntezę oligoeteroli z zastosowaniem innych związków azacyklicznych z grupami aminowymi, amidowymi lub imidowymi, które do tej pory nie reagowały ze wspomnianymi oksiranami.

2

Fasteners of bainitic steels manufactured by drawing and forging

Kuziak R., Milenin A., Paćko M., Pietrzyk M.

Hutnik, Wiadomości Hutnicze

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2011

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Vol. 78, nr 1

74-77

EN

Modelling techniques, capable of solving various problems occurring in industrial metal forming processes, are used in this paper to simulate the entire chain of manufacturing of connecting parts. The objective of simulations is assessment of possibility of introduction of new steel with higher strength than conventional grades. DP steel and new generation bainitic steel are considered. Sequence composed of hot rolling, drawing, cold forging and cutting is analyzed. Particular attention is put on the drawing, as a process which controls the properties of the final product. Selected results of numerical simulation are presented and discussed.

PL

Metody modelowania, pozwalające rozwiązywać problemy występujące w przemysłowych procesach przeróbki plastycznej, są wykorzystane w niniejszej pracy do symulacji cyklu produkcji elementów złącznych. Badano zachowanie się odkształcanego materiału na różnych etapach wytwarzania. Celem symulacji jest ocena możliwości wprowadzenia do produkcji nowych stali o wyższej wytrzymałości. Rozważono stal DP i stal bainityczną nowej generacji. Szczególną uwagę poświęcono procesowi ciągnienia, który ma istotny wpływ na własności gotowego wyrobu. W pracy zamieszczono i omówiono wybrane wyniki symulacji.

3

Crack initiation in steel parts working in boilers and steam pipelines

Renowicz D., Cieśla M.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 21, nr 2

49-52

EN

Purpose: The purpose of this paper is to identify the influence of loading history and the processes of material degradation on the crack initiation and on durability under thermo-mechanical fatigue conditions. Design/methodology/approach: Based on the operation data, the conditions of laboratory examinations of specimens were determined. A specialist apparatus unit was used for the examination, enabling the simulation of any spectrum of mechanical load and temperature changes. Findings: The material durability criterion has been defined based on an energy related approach to the problem of crack initiation in steels which work under thermal fatigue conditions. Research limitations/implications: In the case discussed, i.e. a pipeline part, the present criteria should be expanded with critical values describing the total length of cracks initiated on the internal surface of a specimen. Practical implications: The paper refers to the research on steel 10H2M (10CrMo.910) used in the conventional boilers, superheaters and pipelines in power plants. Originality/value: Originality of the paper is the methodology of the lifetime prediction of steam pipeline parts working in thermo-mechanical fatigue conditions.

4

High strength hot rolled and aged microalloyed 5% Ni steel

Lis A. K., Lis J.

Journal of Achievements in Materials and Manufacturing Engineering

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2006

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Vol. 18, nr 1-2

37--42

EN

Purpose: Purpose of this paper was to give information about low temperature strength and impact CharpyV toughness of low carbon microalloyed 5%Ni bainitic steel after thermomechanical rolling (TMR) or thermomechanical controlled processing (TMCP) and ageing at different temperatures: 580°C/2 h, 640°C/1h and 680°C/1h. Design/methodology/approach: The tensile strength tests were performed at -196, -60 and 20°C and Charpy V samples were broken at -100, -80, -60, -40, -20 and 20°C temperatures. The tensile strength TS, yield strength YS, elongation A5 and reduction of area RA were established from tensile experiments. After TMCP 16 mm steel plate had YS = 730MPa, TS = 950 MPa, A5 = 22,5% and RA = 61% and impact energy > 50 J at -196°C. Findings: The best combination of mechanical properties; yield strength and Charpy V toughness was achieved for steel after TMR and ageing 580°C/ 2h; YS = 800MPa, TS = 900 MPa, A5 = 22.5%, at -1000C KVmin.= 110 J. Research limitations/implications: The precise methodology for retained austenite identification and its amount content determination in the investigated microstructures is still metallographic problem which needs to be resolved. Practical implications: The best combination of yield strength and Charpy V toughness was achieved for steel after TMR and ageing 580°C/ 2h. At liquid nitrogen temperature ultrahigh strength properties were: YS = 1140 MPa, TS = 1280 MPa, A5 = 26%, RA = 55% and KV 122 J at -100°C. Originality/value: The detailed microstructure examination of the steel with optical and mainly scanning transmission electron microscopy was needed to explain its good properties at very low temperature. TRIP effect was observed due to the presence of highly alloyed retained austenite in the microstructure. That type of steel may be used for contemporary military and structural applications working at low temperatures.