Influence Factors of Low Hardness of Gray Iron Castings
Author of the article:LIU Dewang;JIANG Jianzhu
Author's Workplace：Foundry Branch,Shaaxi Fast Auto Drive Group Co.,Ltd.,Baoji 722409,China
Key Words：hardness alloying microelement inoculation opening time
Abstract：
Based on the practice of casting,the test results of metallographic structure and body hardness of cast iron were obtained from the three aspects of ingredients,alloying and controlling the time of opening sand mould,the main reasons of low batch hardness of gray cast iron were analyzed.The microstructure and hardness of gray cast iron were improved by adjusting ingredients ratio,treating molten iron with silicon carbide and alloying with tin iron.The results show that 20%~50%of the return ingredients and some scrap steel containing chromium elements are used in the gray cast iron,and the tin content of the casting is adjusted to 0.04%~0.06%,which can produce qualified gray cast iron with stable hardness and improve the casting quality.
