Preparation effect of mould systems on microstructure and mechanical properties of spheroidised graphite iron
This study is based on evaluation of microstructure and mechanical properties such as tensile strength, Brinell hardness and Charpy impact test of as-cast spheroidal graphite iron using sandwich techniques in different mould systems viz. green sand mould, dry sand mould and CO2 sand mould under varying cooling rates.
EVALUATION OF DUCTILE IRON PRODUCED USING ROTARY FURNACE WITH VARIABLE COMPOSITIONS OF MAGNESIUM ADDITION
Automobile scrap of engine block was the scrap used and initially analyzed with optical light emission spectroscopy for its chemical composition. Forty kilograms (40 kg) of the engine block (grey cast iron) was charged with 0.5 kg graphite (in powder form) and 2 kg calcium tri-oxo carbonate (iv) salt (CaCO3) (flux) into a rotary furnace of 100 kg capacity fired with diesel fuel. The charges in the rotary furnace were heated to a tapping temperature of 1420 o C using inserted thermocouple with temperature controller to monitor the temperature. 0.25 kg calcium carbide (CaC2) was added to the charge in the furnace after 1420 o C melt, before tapping for desulphurization. Three consecutive tappings were made designated A, B and C poured into the prepared steel ladle via sandwich process. 3 %w/w magnesium (Mg), 2.5 %w/w Mg and 1.5 %w/w Mg by weight of the metal treated in the ladle was used to treat melts in ladles A, B and C respectively. Thereafter, the treated melts was poured into already prepared moulds where solidification took place and the as-cast ductile iron of diameter 20 mm by 200 mm length was produced. The as-cast cast iron was also analyzed with mass spectrometric analyzer machine to determine its chemical compositions and its confirmed that the % Carbon and Silicon were within the range of cast iron. Then, tensile, hardness and micro structural analysis were carried out on the as- cast ductile iron using standard methods and machines. The microstructures revealed that as-cast ductile iron from steel ladles A and B contained nodules both un-etched and when etched with 2 % Nital while cast produced from melt in ladle C revealed a flake graphite cast iron. Keywords- Evaluation, sandwich, mechanical properties, metallographic examination, ductile iron, rotary furnace
Appropriated Pasts: Indigenous Peoples and the Colonial Culture of Archaeology
Chapter 1 Colonial Culture of Archaeology Chapter 2 Progressivism: The Invention of Prehistory Chapter 3 Antiquation: Aboriginal Peoples as Living Fossils Chapter 4 Migrationism: The Archaeology of Dispossession Chapter 5 Diffusionism: The Archaeology of Alienation Chapter 6 Subjectation: Appropration Through Science Chapter 7 Shared Nations: The New Appropriation Chapter 8 Partnerships: Pathways to a Decolonised Practice Chapter 9 References Chapter 10 Index