Ningbo Yinzhou Leisheng Machinery Co.,Ltd , https://www.nblscasting.com
The relationship between the shell type and the template temperature and the crust time. If the template temperature is not enough or the shelling time is too early, the shell tooth surface portion cannot be fully cured. Long time, the sand is easy to fall off, resulting in rough surface of the shell tooth surface, affecting the quality of the cast tooth surface. After this kind of situation, the double cone rotary vacuum dryer can be used in the drying box for heating for a period of time before use. The curing temperature is generally 240 to 260 °C.
The shell-type demoulding should carefully clean the residual sand in the shell type, transport and store it, and the shell-shaped tooth surface should not be damaged. When assembling the shell type before casting, the sand should not fall into the sand. The casting temperature is low, and the contour of the tooth surface is unclear, inclusions, pores, etc., and the root of the tooth is also prone to wrinkles, but the casting temperature is too high, and it is easy to produce sticky sand. The suitable casting temperature is 1400 ~ 1450 °C.
Heat treatment process heating equipment: 45kW box type electric furnace quenching equipment: coal-fired salt bath furnace, thermocouple temperature measuring salt bath: nitrate, nitrite heat treatment process. If the as-cast carbide is excessive or distributed in a network, it is difficult to machine, and a high-temperature graphitization annealing process can be added before roughing. Mechanical properties The mechanical properties of the gear material were taken from a wedge-shaped sample cast with molten iron and heat treated with the gear in the same furnace.