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Feeding and Cooling and Time of Thermal Treatment of a Massive Bush Made of the Complex Aluminum Bronze Cast by the Lost Foam

Just P., Pisarek B. P.

Archives of Foundry Engineering

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2014

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Vol. 14, iss. 4

39--44

EN

Small additions of Cr, Mo and W to aluminium-iron-nickel bronze are mostly located in phases &kappa i (i=II; III; IV),and next in phase &alpha (in the matrix) and phase γ2. They raise the temperature of the phase transformations in aluminium bronzes as well as the casts’ abrasive and adhesive wear resistance. The paper presents a selection of feeding elements and thermal treatment times which guarantees structure stability, for a cast of a massive bush working at an elevated temperature (650–750°C) made by means of the lost foam technology out of composite aluminium bronze. So far, there have been no analyses of the phenomena characteristic to the examined bronze which accompany the process of its solidification during gasification of the EPS pattern. There are also no guidelines for designing risers and steel internal chill for casts made of this bronze. The work identifies the type and location of the existing defects in the mould’s cast. It also proposes a solution to the manner of its feeding and cooling which compensates the significant volume contraction of bronze and effectively removes the formed gases from the area of mould solidification. Another important aspect of the performed research was establishing the duration time of bronze annealing at the temperature of 750°C which guarantees stabilization of the changes in the bronze microstructure – stabilization of the changes in the bronze HB hardness.

2

Structure and technological properties of AlSi12 – (SiC_p + Cg_p) composites

Dolata-Grosz A., Dyzia M., Śleziona J.

Archives of Foundry Engineering

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2008

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Vol. 8, iss. 1

43-46

EN

In the article the structure and technological properties of aluminium cast composites with ceramic particles have been presented. Evaluation of casting properties of selected composite materials was made based on spiral tests. The differences occurring in solidification curves for materials reinforcing by silicon carbide, amorphous glass carbon particles and mixture of silicon carbide and glassy carbon particles were compared. On the basis of macro - and microstructural investigations of composite ingots after solidification at the same conditions the distribution of ceramic particles were estimated. The hardness on the cross section of formed composite ingots were presented in the graphic form.

3

Nitrogen as an alloying addition improving the erosive-corrosion resistance of chromium-nickel-molybdenum cast steel. Pt. 2, Investigating the properties of cast alloys

Pirowski Z.

Prace Instytutu Odlewnictwa

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1998

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R. 48, z. 1-2

89-106

EN

Laboratory tests were carried out on specimens of a Cr-Ni-Mo cast steel containing nitrogen in the range of 0.1-0.5 %. The procedure of manufacturing this alloy was described in Part I of the present study. In Part II the hardness was measurend, metallographic examinations were made, the volume fraction of ferrite delta and the ferrite/matrix phase boundary were determined, and finally the erosive-corrosion wear in the medium of chloride ions was investigated. In the alloy in as-cast condition a strong relationship between the rate of wear, chemical composition and the measured parameters of structure was observed to exist. The favourable role of nitrogen in increasing the erosion resistance of the examined cast steel was proved.

PL

Przeprowadzono badania laboratoryjne próbek staliwa Cr-Ni-Mo z zawartością azotu w zakresie 0,1-0,5 %. Sposób uzyskania tych stopów omówiono w części 1. Obecnie dokonano pomiarów twardości, poczyniono obserwacje metalograficzne, określono objętościowy udział ferrytu delta i powierzchnię rozdziału faz ferryt/osnowa oraz przeprowadzono badania zużycia erozyjno-korozyjnego w środowisku jonów chlorkowych. Stwierdzono, że stopy w stanie lanym wykazują silną zależność tego zużycia od składu chemicznego i mierzonych parametrów struktury. Wykazano korzystną rolę azotu w zwiększeniu odporności erozyjnej badanego staliwa.