Method for controlling temperature rise in secondary combustion of vacuum refining exhaust gas

Abstract

The invention discloses a method for controlling temperature rise in secondary combustion of vacuum refining exhaust gas. According to the method, at the early stage of RH decarburization, only when the vacuum degree reaches 0.6kpa, an oxygen lance is controlled to go down for blowing oxygen, the blowing oxygen flow is reduced along with the increase of time; at the middle and later periods of RH decarburization, the blowing oxygen flow is reduced continuously, the temperature rise amplitude in the secondary combustion reaches 15-20 DEG C, so that formation of cool steel in a hot bending pipe is greatly lowered, the temperature in a groove is improved, temperature drop in RH processing is reduced, and the purity and components of molten steel are not affected.

Description

technical field [0001] The invention relates to continuous casting control technology, more specifically, to a control method for secondary combustion temperature rise of vacuum refining waste gas. Background technique [0002] With the continuous increase of RH processing capacity, the cold steel in the vacuum tank is also increasing, and most of the cold steel accumulates in the hot bend pipe, which greatly affects the pumping capacity of RH, thus causing a series of quality problems; at the same time, due to the The irregular peeling off of cold steel will cause abnormal temperature in the tank or abnormal composition of molten steel, resulting in abnormal quality. [0003] There are currently only two ways to remove the cold steel in the tank: 1. Replace the hot bend pipe, but it takes a long time to replace the hot bend pipe. The cycle is long and the workload is heavy. 2. Mainly use high-flow COG baking, but after high-flow baking, you must use general light-treated ...

AI Technical Summary

Problems solved by technology

[0002] With the continuous increase of RH processing capacity, the cold steel in the vacuum tank is also increasing, and most of the cold steel accumulates in the hot bend pipe, which greatly affects the pumping capacity of RH, thus causing a series of quality problems; at the same time, due to the Irregular spalling of cold steel will cause abnormal temperature in the tank or abnormal composition of molten steel, resulting in abnormal quality

[0003] There are currently only two ways to remove the cold steel in the tank: 1. Replace the hot bend pipe, but it takes a long time to replace the hot bend pipe. Long cycle and heavy workload

2. Mainly use high-flow COG baking, but after high-flow baking, you must use general light-treated steel to clean the iron oxide at the bottom of the tank, but when the production plan is all RH-treated steel , it is impossible to bake with large flow

In addition, high-flow baking needs to consume a lot of COG and oxygen, and the effect of cooling steel in the bending pipe is not very obvious.

[0004] In addition, when the temperature of molten steel is low before RH treatment, the only means at present is to blow oxygen into the molten steel and add aluminum alloy at the same time to carry out chemical heating, but this method not only increases the consumption of oxygen and aluminum alloy, but also brings more Much Al 2 o 3 Inclusions affect the purity of molten steel

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