Formation Mechanism and Prevention Measures of Inoculating Defects in Cast Iron
Author of the article:CHENG Fengjun;PAN Anxia;LUO Guangsi
Author's Workplace：Changzhou Vocational Institute of Industry,Changzhou 213164,China
Key Words：cast iron microstructure defect inoculation
Abstract：
The morphology of fractal graphite and D-type graphite of high nickel austenite nodular cast iron were studied.The results show that the defects are directly related to the precipitation time of austenite and graphite during solidification.When a large amount of austenite precipitates,but the graphite precipitates seriously,it is easy to form abnormal structure.When the preference of graphite precipitation increases,it is easy to form normal structure.Poor instillation of nodular cast iron will lead to a serious lag in graphite precipitation and an earlier timing of austenite precipitation,resulting in the formation of broken graphite,Spiking dendrite,antileucorrhoea,leucorrhoea and other defects.In production practice,according to the different types of defects,changing inoculating amount,inoculating agent type,inoculating agent particle size,inoculating mode,inoculating temperature or using special inoculating agent can effectively prevent the formation of defects.
