Ductile iron precision machining is a kind of technology developed in the 20th century, the comprehensive performance of nodular cast iron is close to each other. Steel, formally based on this feature, ductile iron can be used to cast some of the complex forces, for strength, toughness has a higher demand for parts, ductile iron precision machining parts after high-speed development, is a very wide range of materials. Ductile iron is obtained by ballning and inoculation to obtain spherical graphite, effectively improve the mechanical properties of cast iron, in particular, improve the plasticity and toughness. Here Xiaobian speaking about the ball melt processing of the specific process of heat treatment.

1, heat treatment process.

Lathe castings as a large castings must be heat treated to improve their performance and improve the inherent quality, so that heat treatment is one of the most important processes. General heat treatment does not change the shape of the casting and the overall chemical composition, but to change the internal microstructure of the casting, or change the composition of the casting surface to improve the intrinsic quality of the casting.

2, complete annealing with isothermal annealing.

Complete annealing is also called recrystallization annealing, referred to as annealing, this process is mainly used for hypoeutects of various carbon steel and alloy steel casting and forging and hot-rolled profiles, generally as a heavy The final heat treatment of the pieces, or the preheating of some castings.

3, spheroidized annealing.

Spheroidizing annealing is mainly used for alloy tool steels. Its main function is to reduce the hardness, improve the machinability of castings, and prepare for subsequent quenching.

4, to stress annealing.

De-stress annealing is also called low-temperature annealing, this annealing is mainly to eliminate the residual stress castings. If the stress of the casting is not eliminated, the casting will deform and crack after a certain period of time, or after the process.

Only strictly control the production process of ductile iron precision machining, strict product quality, in order to produce qualified castings.