Heat treatment equipment for nodular cast iron grinding ball

According to the characteristics of Si Mn alloyed ductile iron grinding ball, the heat treatment equipment should have the characteristics of high cost performance and low production cost. After years of efforts, we have developed automatic heat treatment line and grinding ball water-based heat treatment production line system. The automatic heat treatment line consists of five parts: basket return and grinding ball preheating system, gas shielded heating and holding furnace, water-based quenching treatment center, frequency conversion speed regulating mesh belt tempering (isothermal) furnace and automatic control detection system. At present, there are three production lines with an annual output of 20000 tons of water based quenching heat treatment unit, large ball water based quenching heat treatment automatic line and small ball water based quenching heat treatment automatic line.

The heating part of the automatic heat treatment line uses a basket to load balls. The basket automatically pushes materials in the closed track according to the set feeding rhythm. The whole heating process is divided into two independent units, preheating and heating. The high-temperature heating unit uses furnace gas protection to reduce the oxidation and decarburization of grinding balls. After the grinding ball enters the water-based quenching unit, the temperature of grinding ball and quenching medium shall be controlled, and the automatic closed-loop regulation shall be realized. The heat treatment line is equipped with a water-based medium automatic control cooling and heating system and a grinding ball temperature automatic adjustment system, which enable the closed-loop automatic adjustment of the water-based medium and grinding ball temperature, and better solve the control guarantee problem of the grinding ball quenching process. Frequency conversion speed regulating mesh belt furnace is adopted for tempering. The mesh belt furnace has accurate temperature control, so that the grinding balls are evenly distributed on the mesh belt. Compared with the traditional grinding ball tempering furnace, the cost of the material basket and energy consumption are saved. The tempered grinding balls directly fall into the hopper from the mesh belt furnace.

The automatic line for water based quenching and heat treatment of grinding balls can not only complete the continuous cooling+tempering process of Si Mn alloyed ductile iron grinding balls, but also simulate the process of near isothermal treatment, and can also process grinding balls of other materials such as high and low chromium.