Nitrogen-filling electroslag process for cavity of nitrogen-containing steel hollow blank

Abstract

The invention particularly relates to a nitrogen-filling electroslag process for a cavity of a nitrogen-containing steel hollow blank, which is different from a common process in which nitrogen is added into an electrode blank of nitrogen-containing steel and then electroslag is carried out. The process is characterized in that nitrogen is not added during smelting of an electrode blank, a nitrogen-free hollow electrode blank is adopted, nitrogen is injected from a reserved hole during electroslag, nitrogen is added into steel through the physical and chemical reaction of nitrogen and steel slag, the nitrogen flow is controlled according to the nitrogen content of different steel types, and alloying of the nitrogen element is completed in the electroslag remelting process. The process can be applied to common electroslag equipment only, and a special pressurizing electroslag furnace high in price does not need to be arranged. Due to the fact that the blank is a hollow blank, the hot spot is not in the center of a molten pool, the shape of an electroslag molten pool is greatly improved, the molten pool tends to be in a flat state, the consistency of internal and external crystalline states of an ingot is higher, redundant nitrogen overflows from the periphery to form a protective atmosphere, oxygen increasing and hydrogen increasing of molten steel are avoided, the alloying target of the nitrogen element can be easily achieved, and the quality of the electroslag ingot can be improved.

Description

technical field [0001] The invention belongs to the category of metallurgical technology, and specifically relates to a nitrogen-containing steel hollow billet cavity nitrogen-filled electroslag process. By using the electroslag process, electrode billets containing no nitrogen can also be used to produce nitrogen-containing electrode billets with a maximum nitrogen content of 0.080%. The steel type simplifies the production process of the electroslag nitrogen-containing steel electrode billet, improves the efficiency, and does not prolong the electroslag remelting time, which can reduce the difficulty of production, reduce the cost consumption of the electrode billet, and obtain higher production efficiency. Background technique [0002] At present, in the nitrogen-containing steel production process that requires electroslag, the most commonly used is to add nitrogen element to the steel when the electrode blank is smelted, and there is also a pressurized nitrogen-filled el...

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Problems solved by technology

Nitrogen is generally added to the electrode billet by blowing nitrogen into the steel or adding a nitrided alloy. When nitrogen is blown into the nitrogen, the speed of nitrogen increase is slow, and it must be carried out after VD. Long-term nitrogen blowing after VD will increase power consumption and corrosion of refractory materials, offsetting The VD degassing effect increases the gas and inclusion content in the steel and deteriorates the quality of the steel; the use of pressurized electroslag requires special sealed electroslag equipment, and the value of a single equipment is 10 times that of ordinary electroslag equipment, which is expensive and cannot be used. The economical production of non-high value-added products is only used in the production of a few special products and cannot be popularized and applied. Therefore, it is necessary to develop a more simplified manufacturing process for nitrogen-containing steel that requires electroslag

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