Effects of cooling rate on vermicular graphite percentage in a brake drum produced by onestep cored wire injection

作     者：Yu-shuang Feng Ze-sheng Ji He-sheng Wu Yong-cheng Feng 

作者机构：School of Materials Science and Engineering Harbin University of Science and Technology Harbin Kedewei Metallurgy Co. Ltd. Shandong Ductile Iron Pipes Co. Ltd. 

出 版 物：《China Foundry》 (中国铸造（英文版）)

年 卷 期：2015年第12卷第5期

页      面：349-353页

核心收录：

学科分类：08[工学] 080502[工学-材料学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

基　　金：financially supported by the Foundation of Heilongjiang Educational Committee(Grant No.12531116) the Harbin Special Funds for Creative Talents in Science and Technology(Grant No.2013RFQXJ102) 

主　　题：cored wire injection in one-step vermicular graphite cast iron cooling rate vermicular graphite percentage brake drum 

摘      要：In this research, a vermicular graphite cast iron brake drum was produced by cored wire injection in a one-step method. Silica sand and low-density alumina-silicate ceramic were used as molding materials in order to investigate the effect of cooling rate on percentage of vermicular graphite and mechanical properties of the brake drum casting. Several thermocouples were inserted into the casting in the desired positions to measure the temperature change. By means of one-step cored wire injection, the two residual concentrations of Mg and RE were effectively controlled in the ranges of 0.013%-0.017% and 0.019%-0.025%, respectively, which are crucial for the production of vermicular graphite cast iron and the formation of vermicular graphite. In addition, the cooling rate had a significant effect on the vermicular graphite percentage. In the case of the silica mold brake drum casting, there was an obvious difference in the cooling rate with the wall change, leading to a change in vermicular graphite percentage from 70.8% to 90%. In the low-density alumina-silicate ceramic mold casting, no obvious change in temperature was detected by the thermocouples and the percentage of the vermicular graphite was stable at 85%. Therefore, the vermicular graphite cast iron brake drum with a better combination of mechanical properties could be obtained.