Papers by Keyword: O

Abstract: Inoculation is a treatment applied to the liquid base iron, to supply one or more elements, such as Al, Ba, Ca, Zr, Sr, Ce, La etc. with active roles in developing graphite nucleation sites. The efficiency of inoculants is directly dependent on the sulphur level: lower sulphur, lower inoculating power or unpredictable results. The objective of this paper is to examine the effects of a S and O containing inoculant enhancer [S,O,Al,Ca-FeSi alloy] to conventional Ca,Ba-FeSi alloy, in the mold treatment of electrically melted grey iron at 0.035%S, 0.002%Al, 0.0005%Zr, (%Mn) x (%S) < 0.02. The wedge test samples [W3 – ASTM A367] were used to evaluate the influence of the cooling rate and inoculation on the carbides formation. It was re-confirmed that for above mentioned critical chemistry conditions, this iron is sensitive to chill formation, despite the carbon equivalent level at 3.8%. Inoculation enhancement increased the effectiveness of the Ca,Ba-FeSi standard inoculant.

Abstract: The objective of this research paper is to examine the effects of adding an oxy-sulphide inoculant enhancer alloy [OS-IE = S,O,Al,Mg-CaSi alloy] to a conventional CaBa-FeSi alloy and to examine the graphite phase characteristics in these irons, as affected by different in the mould inoculants, for resin sand mould castings. The surface layer of all the Mg,RE-FeSi treated compacted / vermicular graphite cast iron samples with 0.018 – 0.023% Mg_res is influenced by S diffusion from Furan Resin–P-Toluol Sulphonic Acid (PTSA). The graphite phase is strongly influenced in this surface layer. Inoculation has a visible, beneficial effect in both the surface layer and the body of casting. Even with the highest solidification rate, at the surface layer of the 25mm round bar samples, the structure has the lowest graphite nodularity (15-20%), due to the sulphur content in the mould binder, in contrast with 40-50% nodularity in the casting body. Adding two inoculant type alloys Ca,Ba-FeSi + [OS-IE], led to the highest compacted / vermicular graphite formation. Inoculation with [OS-IE] only appears to encourage the formation of a high number of small graphite nodules that also display higher nodularity. This is represented by the second highest levels for circularity and sphericity shape factors at a much smaller inoculant addition, compared with a conventional Ca,Ba-FeSi inoculant addition. Inoculation with oxide-forming elements or pairing oxy-sulphide inoculant enhancer with commercial inoculants appears to be an economical alternative to rare earth (RE) based inoculants in compacted / vermicular graphite iron casting production.