Effect of Melting and Pouring Conditions on Structures of Leaded Tin Bronze Castings

연청동주물(鉛靑銅鑄物)의 조직(組織)에 미치는 용해(熔解) 및 주입조건(鑄入條件)의 영향(影響)에 관한 연구(硏究)

The effects of melting and casting conditions on cast structures of Cu-Sn-Pb alloys were studied. Specimens were prepared at different pouring temperatures of $1100^{\circ}C$ to $1260^{\circ}C$ with use of various kind of molds, green sand mold, $CO_2$ sand mold, shell mold, furan sand mold and metallic mold. (1) The transition of equiaxed to columnar structure greatly influenced by adding elements and mold binders. (2) The change of equiaxed structure according to pouring temperatures were expressed by separation theory. Lower pouring temperature and rapid cooling rate increase hardness and it's further increase was shown in the region of columnar structure. (3) Proper controls of pouring temperature, cooling rate and mold binder were important factors to improve wear properties of Cu-Sn-Pb alloys castings.