The Relation between Reaction Chamber Design of In-mold Process and the quality of Furan Resin Mold Spheroidal Graphite Cast Iron Casting

• Main Authors: Chi-Chen Yeh, 葉吉鎮
• Other Authors: Rong-Shean Yang
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/66781533064891966167

碩士 === 逢甲大學 === 機械工程學所 === 92 === The objective of this study is to investigate the effect of the reaction chamber design (inlet and outlet cross section area ratio, nodulant and reaction chamber height ratio, reaction chamber shape, addition of the reaction agent etc., ) of in-mold process on the quality (tensile property, metallographic microstructure) of spheroidal graphite cast iron casting by furan resin mold. The hardness distribution and the repeatability of casting quality by the statistic method are also studied in this research. The results of this study indicate that：(1) when the reaction chamber inlet and outlet cross section area ratio is 1：0.8, the casting quality of spheroidal graphite cast iron casting is the best. The nodularity is 91.5%, the nodule counts is 315 counts/mm2, the tensile strength is 50.96kg/mm2, and the elongation is 21.4%. (2) When the nodulant to the reaction chamber height ratio is 2/3, the metallographic microstructure, nodularity, nodule counts, and the tensile strength of casting are better than the other two height ratios. (3) When the shape of the reaction chamber is designed as a cubic, the nodularity and the mechanical properties are the best. Either the modulus increased (cylindric) or decreased (rectangular), the metallographic microstructure and the mechanical properties were toward to worse. (4) When the inoculant (used as the cover agent) and the nodulant are added in the same time to manufacture the spheroidal graphite cast iron casting of the furan mold, the casting results indicate that the nodularity is bad, and the casting become flake graphite cast iron. (5) For the hardness distribution on the top plane of casting, the hardest spot is at the end side far away the riser and the softest spot is at the side near of riser. The sequence of the average hardness of each cross section planes is：section I＞section II＞section III. From the view point of hardness distribution, the trend of hardness matches the cooling sequence of the casting. (6) Use the statistic method of the Wilcoxon sign test to analyze the repeatability of casting quality (tensile strength), the results indicate the assumption is concluded i.e. the sample values (tensile strength) to the average values is so closely. In the other words, it has high confidence level. So it can be concluded that the repeatability of casting quality is good.