What Is The Annealing Process of Silica Sol Precision Casting Equipment

The production of silica sol precision casting equipment requires many professional process technologies, among which annealing is one. So what is the annealing process of precision casting equipment? Below, the editor of precision casting equipment will tell you.

Recrystallization annealing is a metal heat treatment process in which wear-resistant castings undergo phase transformation recrystallization once during heating and cooling, hence it is called recrystallization annealing, often abbreviated as annealing. The metal is slowly heated to a certain temperature, maintained for a sufficient time, and then cooled at an appropriate rate (usually slow cooling, sometimes controlled cooling).

The recrystallization annealing process of silica sol precision casting is: slowly heating to 30-50 ℃ above Ac1, maintaining for an appropriate period of time, and then slowly cooling down. Through the transformation of pearlite into austenite during the heating process (first round of phase transformation recrystallization) and the opposite second round of phase transformation recrystallization during the cooling process, pearlite with finer grains, thicker layers, and uniform structure is formed. The annealing temperature of silica sol precision casting above Ac3, which causes complete recrystallization of steel, is called complete annealing. The annealing temperature between Ac1 and Ac3 or Ac1 and Acm, which causes partial recrystallization of steel, is called incomplete annealing.

The former is mainly used for castings of hypoeutectoid steel to eliminate structural defects, make the structure finer and more uniform, and improve the plasticity and toughness of steel parts. The latter is mainly used for medium carbon, high carbon steel, and low-alloy steel castings. In addition, the annealing temperature of hypereutectoid steel balls between Ac1 and Acm is also incomplete annealing.