1. What are the basic tasks of steel making? By what means?
The basic tasks of steel making are decarburization, dephosphorization, desulfurization, deoxidation, removal of harmful gases and non-metallic inclusions, increase of temperature, and adjustment of molten steel composition.
Oxygen supply, slagging, agitation, and alloying are the means to accomplish the steel making task.
2.What is the main role of steel making in adding dolomite in converter?
Dolomite is a slag-regulating agent, which is divided into raw dolomite and light-burned dolomite. According to the needs of slag splashing protection technology, the amount of MgO in the slag is added to maintain saturation or to reduce the erosion of the initial slag on the furnace lining, the final slag can be made sticky, and the slag splashing requirement is achieved after tapping.
3. Combine the situation before, during and after the blowing, and briefly describe the operation of the constant pressure gun.
The constant flow variable gun position operation is to keep the oxygen supply flow constant during the blowing process of a furnace steel, and control the blowing by changing the position of the oxygen flow and the molten pool by adjusting the gun position. Most manufacturers in China use a staged constant flow variable gun position operation. Oxygen lance operation is not exactly the same due to different tonnages of the converter, nozzle structure, raw material conditions and steel grades. There are currently two lance operation modes.
High-low-high-low gun position mode. The open blow gun position is higher, and the initial slag is formed early. When the second batch of rice is added, the gun is lowered at the appropriate time. When the middle slag is blown back, the gun can be added or an appropriate amount of flux can be added to adjust the slag fluidity to shorten the blowing time and the end point. Pull carbon out of steel.
High-low-low gun position mode. The open blow gun position is higher, and the initial slag is formed as soon as possible; the gun position is gradually reduced during the blowing process, and an appropriate amount of flux is added in the middle of the blowing to adjust the slag fluidity, and the carbon steel is extracted at the end point.