蠕墨铸铁的性能特点和生产控制

Property Characterics and Production Control of Vermicular Graphite Iron

介绍了蠕墨铸铁的起源和性能特点:其强度和韧性虽然略低于球墨铸铁,但比灰铸铁高;其导热性、减震性和铸造性能虽然比灰铸铁略差,但优于球墨铸铁。《蠕墨铸铁件》国家标准(GB/T 26655—2011)将蠕墨铸铁分为5个牌号,分别是RuT300、RuT350、RuT400、RuT450、RuT500。阐述了C、Si、Mn、S、P五大元素及合金元素的控制、蠕化剂加入量的确定、蠕化处理铁液量的控制、蠕化处理铁液温度的控制和蠕化处理方法。详细叙述了蠕墨铸铁在制动盘、气缸盖、气缸体、排气歧管上的应用,以及冲天炉条件下的“随流冲入法”蠕化处理工艺、冲天炉+保温感应电炉条件下的“引爆法”蠕化处理工艺、“Sinter Cast法”蠕化处理工艺的特点和生产控制方法。

The origin and property characterics were introduced:although its strength and toughness were slightly lower than nodular iron,however higher than gray iron.Its thermo-conductivity,shock absorbability and casting property were slightly than gray iron,however better than nodular iron.The China National Standard Vermicular Graphite Iron Casting(GB/T 26655—2011)divided vermicular graphite iron into 5 grades:RuT300,RuT350,RuT400,RuT450,RuT500.A description was conducted about how to control the 5 basic elements of C,Si,Mn,S,P,and alloying elements,how to determine vermicularizing alloy addition,how to control the weight and temperature of iron melt to be vermicularizng treated,and how to choice the vermicu-larizing process.The application of vermicular graphite iron to the brake disc,cylinder head,cylinder block,exhaust manifold,and as well as,the stream pour-over vermicularizing process under the cupola melting condition,detonating vermicularizing process under cupola+induction furnace,and Sinter Cast process and their production control method were described in detail.