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Evaluation of the Effect of the Cr, Mo, V and W Content in an Al-Si Alloy Used for Pressure Casting on its Proof Stress

Szymczak T., Szymszal J., Gumienny G.

Archives of Foundry Engineering

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2018

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Vol. 18, iss. 2

105--111

EN

The study presents the results of the application of a statistical analysis for the evaluation of the effect of high-melting additions introduced into a pressure cast Al-Si alloy on the obtained level of its proof stress Rp0.2. The base Al-Si alloy used for the tests was a typical alloy used for pressure casting grade EN AC-46000. The base alloy was enriched with high-melting additions, such as: Cr, Mo, V and W. The additions were introduced into the base Al-Si alloy in all the possible combinations. The content of the particular high-melting addition in the Al-Si alloy was within the scope of 0.05 to 0.50%. The investigations were performed on both the base alloy and alloy with the high-melting element additions. Within the implementation of the studies, the values of Rp0.2 were determined for all the considered chemical compositions of the Al-Si alloy. A database was created for the statistical analysis, containing the independent variables (chemical composition data) and dependent variables (examined Rp0.2 values). The performed statistical analysis aimed at determining whether the examined high-melting additions had a significant effect on the level of Rp0.2 of the Al-Si alloy as well as optimizing their contents in order to obtain the highest values of the Al-Si alloy's proof stress Rp0.2. The analyses showed that each considered high-melting addition introduced into the Al-Si alloy in a proper amount can cause an increase of the proof stress Rp0.2 of the alloy, and the optimal content of each examined high-melting addition in respect of the highest obtained value of Rp0.2 equals 0.05%.

2

Analiza wpływu podwyższonych temperatur na własności wytrzymałościowe prętów zbrojeniowych ze stali B500SP

Michalczyk J., Koczurkiewicz B.

Hutnik, Wiadomości Hutnicze

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2009

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Vol. 76, nr 8

598-600

PL

W pracy przedstawiono wyniki badań wpływu zmian temperatury na własności mechaniczne prętów zbrojeniowych ze stali B500SP. Badania wykonywano z wykorzystaniem maszyny wytrzymałościowej Zwick Z100 wyposażonej w oporowy piec firmy Maytec. Badania przeprowadzono stosując temperatury wygrzewania prętów w zakresie 100÷600 °C przez 360 min. Po wygrzewaniu próbki chłodzono swobodnie. Statyczną próbę rozciągania przeprowadzano w temperaturze otoczenia. Na podstawie prób rozciągania określono umowną granicę plastyczności, wytrzymałość na rozciąganie i wydłużenie badanej stali w funkcji temperatury.

EN

The paper presents the results of investigation into the effect of temperature variations on the mechanical properties of reinforcing bars made of steel B50SP. A Zwick Z100 testing machine equipped with a Maytec resistance furnace was used for tests. The tests where conducted in the temperature range 100÷600 °C while applying a soaking time of 360 min and cooling gravitational. The force and elongation values were recorded. On their basis, the proof stress and tensile strength of the steel tested were determined as a function of temperature.

3

Complex silumins

Pietrowski S.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 24, nr 1

101-105

EN

Purpose: The study presents the results of investigations carried out on silumins with additions of Mg, Ni, Cu, Cr, Mo and W. The silumins containing Mg, Cu and Ni are well-known and commonly used in construction of machines and equipment. Design/methodology/approach: Additions of Cr, Mo and W have not been thoroughly investigated yet. They are considered a new family of innovative cast aluminium alloys. Findings: In Al-Si systems they form silicides, like Cr3Si, Mo3Si, W3Si and intermetallic phases of Al13Cr4Si4, Al12Mo, Al12W and AlWSi. The silicides crystallise in cubic lattice of parameters similar to aluminium and silicon. Research limitations/implications: Therefore they can act as crystallisation substrates and occur as separate phases. The examinations under the microscope and X-ray microanalysis of the linear and point distribution of elements confirmed the presence of the above mentioned phases. A combination of two elements, e.g. Cr and Mo, or Cr and W, was observed to cause the formation of complex silicide layers of Mo3Si and (Cr, Mo)3Si, or Cr3Si as well as (W, Cr)3Si. Originality/value: The presence of the silicides has been indicated as a possible source of the refinement of alpha (Al) and beta (Si) phases. The precipitations of these phases and of the intermetallic phases favour a high degree of the silumins hardening. A characteristic feature is the fact that nucleation and crystallisation of the successive phases takes place at the phase boundaries formed between the previously precipitated phase and solid solution alpha. The studies carried out so far have indicated that in complex silumins at high temperatures crystallise the silicides and peritectic phases of Al12W, AlWSi, Al12Mo and Al13Cr4Si4. Phases alpha or beta are the next ones to crystallise, followed by complex eutectic alpha + beta +Al(Si, Cr, Mo, W, Fe). Further crystallise the phases of Mg2Si, Al3Ni and Al2Cu. The silumins presented here are characterised by high mechanical properties: Rp0,2=320-420MPa, Rm=400-520MPa, A5=0.5-5.0% and elevated hardness of 145-210HB. Further investigations will be carried out to optimise the chemical composition of silumins and the precipitation hardening process parameters to produce alloys characterised by optimum combination of strength, ductility and hardness.

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Analiza wpływu podwyższonych temperatur na własności wytrzymałościowe prętów zbrojeniowych ze stali 18G2-b

Kawałek A., Koczurkiewicz B., Nowosielski Cz.

Hutnik, Wiadomości Hutnicze

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2007

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Vol. 74, nr 6

292-295

PL

W pracy przedstawiono wyniki badań nad wpływem zmian temperatury na własności mechaniczne prętów zbrojeniowych ze stali 18G2-b. Do badań wykorzystano maszynę wytrzymałościową Zwick Z100 wyposażoną w piec oporowy Maytec. Badania prowadzono w zakresie temperatur 20-600 °C stosując czas wygrzewania 30 min. Rejestrowano siłę oraz wartości wydłużeń. Na ich podstawie określono umowną granicę plastyczności i wytrzymałość na rozciąganie badanej stali w funkcji temperatury.

EN

The paper presents the results of investigation into the effect of temperature variations on the mechanical properties of reinforcing bars made of steel 18G2-b. A Zwick Z100 testing machine equipped with a Maytec resistance furnace was used for tests. The tests were conducted in the temperature range of 20-600 °C, while applying a soaking time of 30 min. The force and elongation values were recorded. On their basis, the proof stress and the tensile strength of the steel tested were determined as a function of temperature.