バイオコークスを加炭材として用いた鋳鉄の機械的性質に及ぼす炭素, 窒素量の影響

抄録

  Bio-coke made from green tea biomass is proposed as a substitute foundry coke used to produce cast iron. Since biomass is a natural resource, CO₂ emissions would be zero. If biomass can be used as a substitute for coke, production of low-priced environmentally friendly cast metal could be realized.
  In this study, to examine bio-coke as a substitute, we thus focused on the amount of carbon in bio-coke, collected basic data on the changes in the five main elements and mechanical properties of cast iron when bio-coke is added as a carburizer during the manufacture of cast iron.
  To study the influence of the addition of bio-coke on the properties of cast iron, we made FC25, and investigated the influence of bio-coke on the mechanical properties and matrix of cast iron. We found that the addition of green tea bio-coke produced 1.1% carburization effects. The results of studying mechanical properties also showed that the standard values of FC250 were met, and the tensile strength was higher by about 40MPa from conventional FC250 due to the nitrogen in green tea bio-coke. The nitrogen content of the molten cast iron reached its maximum 360 seconds after the start of bio-coke immersion. It was also found that because the CE value increases due to the carburizing process 360 seconds later, the amount of nitrogen gradually decreases. On the other hand when the bio-coke temperature increased from 1673K to 1873K, the maximum nitrogen content decreased to the minimum of about 117ppm.