The deformation of the EPS pattern in the evaporative pattern casting process using the steel shot as a mold was investigated experimentally. The strain of the plate EPS pattern in the packing process was measured by a strain gauge bonded to the EPS pattern. For uncoated EPS patterns, when the steel shot was packed, the strain of the EPS pattern was slightly greater than when silica sand was packed. By coating with suitable thickness, the strain of the EPS pattern decreased considerably and the effect of the packing material on the strain was not significant.

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  In order to increase the elongation of T6-heat treated JIS AC4C alloy squeeze castings, the effects of Srmodification and grain-refinement by titanium addition on the tensile properties were investigated by varying the secondary dendrite arm spacing between 15 to 30 μm as the coarseness of solidified structures. The effects of Sr-modification and Ti-refinement on the elongation were hardly observed when the structure was fine as a result of rapid solidification. The elongation of castings decreased as the solidified structures became coarser when no molten metal treatment was performed. However, the elongation was increased by Sr-modification. Moreover, the elongation increased more when Ti-refinement in addition to Sr-modification was performed. It was also clarified that the elongation improved with the formation of fine eutectic silicon particles which are hard to crack. In addition, the crack advanced zigzag not only through the Al-Si eutectic region but also across dendrites which grew in a curve due to the cored structure of the segregated titanium.

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  Multi-component white cast irons with varying carbon content from 1.4 to 2.4 mass % and with about the same amount (5 mass %) of each alloying elements Cr, Mo, W, V and Co respectively were prepared to determine the effect of carbon content and heat-treating condition on the heat treatment behaviors. Hardness of as-hardened specimens rise with an increase in carbon up to a certain or critical carbon content and then decrease. Volume fraction of retained austenite (V_γ) increases as carbon content and austenitizing temperature rise. Each specimen tempered after hardening shows a tempered hardness curve with remarkable secondary hardening, which is due to the precipitation of MC and M₆C carbides with extremely high hardness, and V_γ decreases rapidly over a given tempering temperature. It was found that the maximum value of tempered hardness in high carbon iron is obtained from the specimens austenitized at low temperatures and at high temperature in low carbon iron, and that their tempering temperatures range between 773K and 823K.

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  In this study, spheroidal graphite cast iron (FCD450) and mild steel (SS400) were welded by tungsten inert gas (TIG) welding method using cast iron or mild steel welding rods. After welding, microstructure, Vickers hardness and quantitative analysis of welding zone were investigated. The results proved that chill formations in the weld metal decreased easily using hypereutectic cast iron welding rods. Furthermore Ca-Si-Ba inoculant and an aluminum foil were placed in a single V groove of the base metals and they were welded together using hypereutectic cast iron welding rods. In the case where only Ca-Si-Ba inoculant was added, no chill was formed in the weld metal but in the bonded zone of FCD base metal. However, by the addition of 0.6 % aluminum, no chill was formed and the weld metal formed into a ferritic spheroidal graphite structure. Consequently Vickers hardness in the weld metal and in the bonded zone was 239-355HV and 300HV respectively.

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