Wyniki wyszukiwania - Biblioteka Nauki

1

The Impact of Material Selection on Durability of Exhaust Valve Faces of a Ship Engine – A Case Study

100%

Smoleńska H. , Kończewicz W. , Bazychowska S.

Advances in Science and Technology. Research Journal

|

2020

|

tom Vol. 14, no 3

165--174

EN

Two alloys were used in order to extend the service life of marine engine exhaust valve head. Layers of cobalt base alloys were made of the powders with chemical composition as follow: the layer marked L12; C-1.55%; Si-1.21%; Cr-29.7%; W-9%; Ni-2%; Mo<0.01%; Fe-1.7%; Co-54.83% and the layer marked N; C-1.45%; Co-38.9%; Cr24.13%; Ni-10.43%; W-8.75%; Fe-7.64%; Mo-7.56%; Si-2.59%. Base metal was valve steel after heat treatment. It was consisted of: C-0,374%; Cr-9,34%; Mn-0.402%; Ni-0.344%; Si-2.46%; Mo-0.822%; P-0.0162%; S-0.001%. Layers on the valve faces were produced by laser cladding using the HPDL ROFIN DL020 laser. Grinding treatment is a very popular form of regeneration of seat and valve plug adhesions. Properly performed grinding operation ensures dimensional and shape accuracy of the surface from 7 to 5 accuracy class and surface roughness Ra not less than 0.16 μm, depending on the object and method of grinding. The 75H and 150S types are a significantly simplified form of valve plug face grinders. Finishing treatment was carried out with a Chris-Marine AB75H sander on a sanding stand equipped with a compressed air system - the stand was designed by the author. The sander has been set up to the surface of the valve stem so that the grinding angle of the valve faces is 30°+10°. A flat grinding wheel T1CRA54–K was used for machining. The plunge feed was 0.01 mm/rev. The thickness of the welded layer after grinding was 1.2 mm. Both valves were installed in the ship’s engine and were used in real life. After 2000 hours of operation, the valve marked N was damaged. The valve marked L12 showed no damage and was in operation for the next 1000 hours.

2

Influence of graphite as a filler on selected mechanical and structural properties of layered composites with polyester-glass recyclate

100%

Wieczorska A. , Panasiuk K. , Bazychowska S.

Journal of KONBiN

|

2022

|

tom Vol, 52, iss. 2

1--22

EN

The search for recycling methods of composite materials indicated the possibility of using composites with polyester-glass recyclate as structural elements. The main aim of the article was to analyse the influence of the graphite percentage content on the mechanical and structural properties of such composites. Composite materials were made by hand laminating with 10% polyester-glass recyclate and graphite nano-additive. Samples for the static tensile test were prepared, which was carried out in accordance with the applicable standard on a universal testing machine. The obtained results showed that with the increase in the amount of graphite, the properties of the composite decrease; however, dispropor-tionately to the % of its content.

PL

W ramach poszukiwania metod recyklingu materiałów kompozytowych zauważono możliwość zastosowania kompozytów z recyklatem poliestrowo-szklanym jako elementów konstrukcyjnych. Celem zasadniczym artykułu była analiza wpływu zawartości procentowej grafitu na właściwości mechaniczne i strukturalne takich kompozytów. Wykonano materiały kompozytowe metodą laminowania ręcznego z recyklatem poliestrowo-szklanym w ilości 10%, a także nanododatkiem grafitu. Przygotowano próbki do statycznej próby rozciągania, którą przeprowadzono zgodnie z obowiązującą normą na uniwersalnej maszynie wytrzymałościowej. Uzyskane wyniki wykazały, iż wraz ze wzrostem ilości grafitu właściwości kompozytu maleją, jednakże nieproporcjonalnie do jego procentowej zawartości.

3

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

100%

Bazychowska S. , Starosta R. , Dudzik K.

Journal of KONBiN

|

2022

|

tom 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.