Analysis of the Current Situation and Common Problems in the Use of RH Furnace Refractory Materials

Summarized and analyzed the current situation and common problems of the use of refractory materials in RH furnace, and proposed solutions and measures. At the same time, reasonable material selection and design issues for different parts of RH furnace were also discussed.

1 Introduction

Since the introduction of RH vacuum refining equipment in the late 1960s, after more than 50 years, its functions have become increasingly perfect. At present, the metallurgical functions of RH vacuum refining technology include dehydrogenation, decarbonization, deoxidation, desulfurization, control of steel composition and temperature, inclusion control and removal, etc. The variety suitable for smelting has greatly increased, becoming an essential refining equipment for smelting high value-added steel grades such as pipelines, ultra-low carbon steel, silicon steel, etc., and increasing requirements for the performance of refractory materials for RH have been put forward.

Introduction to 2 RH Furnace Magnesium Brick Manufacturers

RH, also known as circulating vacuum degassing method, is a circulating vacuum degassing device developed by Ruhrstahl and Hylas in 1959. It combines vacuum refining with molten steel circulating flow. With the large-scale of steelmaking furnaces, RH treatment equipment has also become larger, and the current world's RH equipment has reached 360t.

Initially, the RH device was mainly aimed at dehydrogenation of molten steel, but later added functions such as vacuum decarburization, vacuum deoxygenation, improvement of molten steel purity, and alloying. The RH method has the advantages of short processing cycle, large production capacity, and good refining effect, making it very suitable for cooperation with large steelmaking furnaces.

The refining functions of the RH furnace are as follows:

1) Degassing of molten steel can be controlled to obtain pure molten steel with H ≤ 0.000 15% and N ≤ 0.002%.

2) Decarburization of molten steel can produce ultra-low carbon steel with C ≤ 0.002% within a 25 minute treatment cycle.

3) Desulfurization and RH additional injection of synthetic slag can produce ultra-low sulfur steel with S ≤ 0.001%.

4) The RH KTB technology is used for heating up, which can reduce the tapping temperature of the converter by 26 ℃; By using the RH-OB method and aluminum blowing oxygen to increase temperature, the heating rate of molten steel can reach 8 ℃ · min-1.

5) Uniform molten steel temperature can maintain a temperature fluctuation of no more than 5 ℃ in the continuous casting tundish.

6) Unify the composition of molten steel and remove inclusions to produce pure steel with T [O] ≤ 0.0015%.

Introduction to various parts of the 3 RH furnace and refractory design