Continuous Annealing Furnace

The continuous annealing furnace is a commonly used style of heat treatment furnace responsible for electrical steel annealing. It serves a purpose of eliminating the internal strain in the cold-rolled steel via a process known as re-crystallization. Re-crystallization is often accompanied by grain growth, which further improves the ductility and workability of the steel. Continuous annealing in the heat treatment equipment also results in the oxidation of the steel’s surface when the carbon in the steel reacts with oxygen-containing atmosphere. Through re-crystallization and decarburization in the continuous annealing furnace, the strip steel obtains the required magnetic properties, hardness, and magnetic aging.

To facilitate re-crystallization and grain growth, it is required that the strip steel should be heated rapidly to the pre-set temperature so that the grains in the lattice structure of steel can be rearranged, and the steel can have improved magnetic properties.

During the working of a continuous annealing furnace, there are two crucial factors that would affect the performance of strip steel: heating and cooling techniques. If customers want to produce a non-oriented silicon steel with exceptional performance, they need to choose the most suitable annealing oven and technique as well according to the desired grades of the silicon steel.

This annealing furnace allows for continuous product input and output. It also enables good uniformity and ductility of the processed steel while delivering high production efficiency. All these features are unrivaled by any previous bell annealing furnaces.

A key component in the continuous annealing furnace is the furnace which is comprised of the heating section, even heating section, first-time cooling section, age hardening, and rapid cooling. According to its intended production capacity, our annealing machine can be designed into the floor-standing or horizontal type. The floor-standing version takes up little space while giving large productivity.

Note
During decarburization, the annealing furnace should maintain a proper heating atmosphere which should not only allows maximum decarburization, but also prevents any occurrence of surface oxidation. Hence, a humidified mixture of hydrogen and nitrogen should be used. Increasing water vapor content contained in the heating atmosphere facilitates decarburization, but it also increases the risk of steel strip oxidation. An appropriate proportion of hydrogen to the whole atmosphere reduces the probability of surface oxidation and ensures a bright surface of the strip steel.