Papers by Keyword: S

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.

Abstract: Al and S co-doped TiO2 (S-Al-TiO2) mesoporous materials as a kind of visible light photo- catalysts are prepared using pyridine as a template through a solid state reaction route. The materials features are characterized by the advanced instruments. The photodegradation kinetic of paclobutra- zol is investigated. It is shown that the doping of S and Al could effectively inhibit the growth of anatase TiO2, both S and Al have entered into the lattice of TiO2. Surface area of 81.3m2/g and narrow pore size distribution (~2.1nm) are presented, it not only enables the visible-light absorption but also promotes photocatalytic property of paclobutrazol. Moreover, within 150 min of visible-light irradiation, the photocatalytic degradation of paclobutrazol approximately follows an order kinetics, and the photodegradation rate in 46.7% and reaction rate constant of 0.00414 min-1 are obtained.

Abstract: Heavy metals and atmosphere pollutants that caused the soil pollution and low air quality are main environmental problems in cities which located in the industrialized regions. Different tree species in urban forest ecosystem have absorption ability to heavy metals in the soil and atmosphere pollutant and ameliorate environmental pollution. However, the influence of different tree species on the absorption ability of different pollutant is not yet clear, and this held up selection suitable tree species in urban forest plantations to improve urban environment. In the study we compered pollution absorption ability of 13 tree species in Shenyang, Northeast China. The results showed that, the adsorption capacity of different tree species on pollutants are different. The highest value of Cu was 9.32 mg kg^-1 found in Berberisthumbergii cv. Atropurpurea, Zn was 51.461 mg kg^-1 in Pinus bungeana, Pb was 7.459 mg kg^-1 in Malus pumila Mill, Cr was 9.841 mg kg^-1 in Buxus microphylla, S was 8916.07 mg kg^-1 in Salix babylonica, Zn was 4678.388 mg kg^-1 in Buxus microphylla. Pollutant concentrations in the same plant species are different in 3 different sample sites. This indicate the contaminated degree of 3 sample sites were different. In our study, Huigong square pollution degree is serious than the Beiling Park and Huishan ecological park. Significant correlation was found between Cu and Cr, Cu and Cl, S and Zn, Cr and Cl (P<0.01) and that between Cu and Zn, Cu and Pb at 0.05 level. The relationship between heavy metals and atmosphere pollutant (S and Cl) indicated that traffic activities could be one of the dominant roles of heavy metal and atmosphere pollution in Shenyang City.

Abstract: Three studies on the oxidation behaviour of austenitic stainless steels were described in the present paper. (1) High temperature oxidation behaviour and its mechanism in austenitic stainless steels with high silicon: Sulfur contained as impurity in steel showed a harmful influence to the oxidation resistance of 19Cr-13Ni-3.5Si stainless steels. It was found that the abnormal oxidation was caused from the surroundings of MnS inclusions. (2) Effect of a small addition of yttrium on high temperature oxidation resistance of Si-containing austenitic stain less steels: The oxidation resistance of 19Cr-10Ni-1.5Si steels was improved remarkably even with only 0.01%Y addition, which is the same concentration as added for de-oxygenation. Y was enriched at the grain boundary of oxide scale and metal-oxide interface. It was suggested that Y-containing steels shoed good oxidation resistance, because the enriched Y at the grain boundary and metal-oxide interface prevented the diffusion of iron and oxygen ions through the oxide scale. (3) Effect of grain size on the oxidation behaviour of austenitic stainless steels: Type 304, 316 and 310 steels with finer grain size showed better oxidation resistance than those with coarser grain size at 850°C. The oxide scale of steels with coarser grain size easily spalled during the cooling process.

Abstract: Multiple P or S hot ion implantation to diamond substrates was performed at 800°C. Optical absorption spectra indicated that instantaneous annealing during hot ion implantation occurs. Temperature dependence of resistance demonstrated that a P as-implanted sample using a homoepitaxial diamond film substrate emerges a weak doping effect. Also on S implantation, a presence of a weak doping effect was observed in an as-implanted sample, but it was suggested that the dopant is not S itself but S and defect complex. However, post-implantation annealing resulted in high resistance of the samples and missing of such weak doping effects.