Process parameters of strip transverse magnetic field induction heating annealing treatment

Transverse magnetic field induction heating annealing treatment is mainly used for recrystallization annealing of cold-rolled low carbon steel strips and annealing to eliminate aging strain phenomena. The purpose of recrystallization annealing is mainly to improve the plasticity and toughness of the steel strip. The purpose of annealing to eliminate strain aging is to maintain the plasticity and stability of the steel strip.

There are two traditional annealing treatment methods for low carbon steel strips. One is annealing the entire steel strip in a protective atmosphere covered ball furnace, and the annealing cycle of each furnace is 16 to 24 hours; the other is uncoiling annealing in a protective atmosphere continuous annealing furnace, and the operating time Short, but the steel strip has strain aging phenomenon after annealing. In addition, both annealing processes have the disadvantages of high energy consumption and low thermal efficiency.

In the 1970s, foreign research used the transverse magnetic field induction heating method to anneal cold-rolled low-carbon steel strips, which achieved certain results and was used in production practice.

The 200~320℃ annealing process is mainly used to eliminate the strain aging phenomenon of thin steel strips. When cold-rolled thin steel strips are rapidly and continuously annealed, due to insufficient recovery and recrystallization annealing time, the resulting annealed structure is not very stable. Under normal temperature, natural aging (i.e., strain aging) will occur. The occurrence of strain aging will reduce the plasticity of the steel strip and increase the brittleness. In severe cases, it will lead to brittle fracture of the steel strip. In order to reduce the strain aging phenomenon, a low-temperature annealing and rapid cooling method of 200 to 300°C is used.