VD furnace is mainly used to refine steel liquid via vacuum degassing treatment, to precisely and finely adjust the component of steel liquid in order to meet the production requirement of special steel and high-quality steel. Through the treatment of VD furnace, the hydrogen content of steel liquid can be less than 1.5-2ppm, the steel liquid inclusion can be denatured and also make the immutable inclusion minimized.
It is mainly used for steel grades with special requirements for gas and inclusion content, like bearing steel, gear steel, military steel and other special purpose steel. Through vacuum treatment, the steel liquid has low gas content, high purity and good quality.
VD process flow: the crane lifts the ladle with steel liquid into the vacuum tank of VD furnace, and manually connects the argon blowing pipe while taking temperature measurement and sampling. Next, the vacuum tank cover car is driven from standby position to the treatment position and the tank cover is closed. Then, Pre-vacuum, vacuum degassing treatment, argon blowing and stirring… after treatment, close vacuum main valve → break the vacuum → lift the tank cover → bridge crane to lift the tank cover to the standby position → temperature sampling, oxygen and hydrogen fixing → stop argon blowing → alloy fine adjustment → add insulation agent → crane to lift the ladle to the casting station.
