The paper presents the effect of manganese on the crystallization process, microstructure and selected properties: cast iron hardness as well as ferrite and pearlite microhardness. The compacted graphite was obtained by Inmold technology. The lack of significant effect on the temperature of the eutectic transformation was demonstrated. On the other hand, a significant reduction in the eutectoid transformation temperature with increasing manganese concentration has been shown. The effect of manganese on microstructure of cast iron with compacted graphite considering casting wall thickness was investigated and described. The nomograms describing the microstructure of compacted graphite iron versus manganese concentration were developed. The effect of manganese on the hardness of cast iron and microhardness of ferrite and pearlite were given.
This paper shows how it is possible to obtain an ausferrite in compacted graphite iron (CGI) without heat treatment of castings. Vermicular graphite in cast iron was obtained using Inmold technology. Molybdenum was used as alloying additive at a concentration from 1.6 to 1.7% and copper at a concentration from 1 to 3%. It was shown that ausferrite could be obtained in CGI through the addition of molybdenum and copper in castings with a wall thickness of 3, 6, 12 and 24 mm. Thereby the expensive heat treatment of castings was eliminated. The investigation focuses on the influence of copper on the crystallization temperature of the graphite eutectic mixture in cast iron with the compacted graphite. It has been shown that copper increases the eutectic crystallization temperature in CGI. It presents how this element influences ausferrite microhardness as well as the hardness of the tested iron alloy. It has been shown that above-mentioned properties increases with increasing the copper concentration.
The paper presents the results of the research on the effect of copper on the crystallization process, microstructure and selected properties
of the compacted graphite iron. Compacted graphite in cast iron was obtained using Inmold process. The study involved the cast iron
containing copper at a concentration up to approximately 4%. The effect of copper on the temperature of the eutectic crystallization as well
as the temperature of start and finish of the austenite transformation was given. It has been shown that copper increases the maximum
temperature of the eutectic transformation approximately by 5C per 1% Cu, and the temperature of the this transformation finish
approximately by 8C per 1% Cu. This element decreases the temperature of the austenite transformation start approximately by 5C per
1% Cu, and the finish of this transformation approximately by 6C per 1% Cu. It was found that in the microstructure of the compacted
graphite iron containing about 3.8% Cu, there are still ferrite precipitations near the compacted graphite. The effect of copper on the
hardness of cast iron and the pearlite microhardness was given. This stems from the high propensity to direct ferritization of this type of
cast iron. It has been shown copper increases the hardness of compacted graphite iron both due to its pearlite forming action as well as
because of the increase in the pearlite microhardness (up to approx. 3% Cu). The conducted studies have shown copper increases the
hardness of the compacted graphite iron approximately by 35 HB per 1% Cu.
This paper presents the results of hypoeutectic 226 grade alloy as well as prepared on its basis Al-Si alloy containing Cr, V and Mo. The
additives tested were added as AlCr15, AlV10 and AlMo8 master alloys. Alloys tested were poured into DTA sampler as well as using
pressure die casting. An amount of Cr, V and Mo additives in alloy poured into DTA sampler comprised within the range approximately
0.05-0.35%. Alloys to pressure die casting contained 0.05-0.20% Cr, V and Mo. The crystallization process was examined using the derivative
thermal analysis (DTA). The microstructure of castings made in the DTA sampler as well as castings made with use of pressure die
casting were examined. The basic mechanical properties of castings made using pressure die casting were defined too. It has been shown
in the DTA curves of Al-Si alloy containing approximately 0.30 and 0.35% Cr, Mo, and V there is an additional thermal effect probably
caused by a peritectic crystallization of intermetallic phases containing the aforementioned additives. These phases have a morphology
similar to the walled and a relatively large size. The analogous phases also occur in pressure die casting alloys containing 0.10% or more
additions of Cr, V and Mo. The appearance of these phases in pressure die casting Al-Si alloys coincides with a decrease in the value of
the tensile strength Rm and the elongation A. It has been shown die castings made of Al-Si alloys containing the aforementioned additives
have a higher Rm and A than 226 alloy.