Effect of Processing Variable Different Foundry Parameter on the Mechanical Properties of Austempered Ductile Irons

• Main Authors: Yang, Zang Chou, 楊鎮州
• Other Authors: T.S. Shih, C.K. Lin
• Format: Others
• Language: zh-TW
• Published: 1997
• Online Access: http://ndltd.ncl.edu.tw/handle/07223750935130206187

碩士 === 國立中央大學 === 機械工程學系 === 85 === Processing variable of different inoculation techniques, chemical compositions (0.6%Cu,0.5%Ni0.5%Cu),and filling rates for producing ductile iron had been evaluatedin this study to see their effects on the as-cast microstructures of different- sectionedductile irons.One process used the ladle inoculation added with ferrosiliconinoculant and 40 ppm bismuth.Another process used the combination of ladle inoculation and stream inoculation.Two stepped plate castings(20 and 35mm;35 and 65mm) werepoured from local foudry shop. The as-cast microstructures of plate castings were compared.The effect ofdifferent inoculation treatments on the mechanical properties of produced platecastings were discussed.Specimens from different locations of two stepped plate castingswere prepared. These specimens were used to conducted two different austempered procedures.One procedure isothermally held at 573K for 180 minutes, and another procedure treatedthe specimens at 663K for 8 minutes and then isothermally holding at 573L for 172 minites, after the solution treatment at 1173K for 90 minites.Mechanical properties of tensilestrength,elonation,impact energy and hardness were tested and compared.