Smelting method of semi-high-speed steel hot-rolled aluminum working roller

Abstract

The invention discloses a smelting method of a semi-high-speed steel hot-rolled aluminum working roller, and belongs to the technical field of manufacturing of rollers. The smelting method comprises the following steps: when forged semi-high-speed steel is discharged to a ladle refining furnace, 1.8-2.2 kg / t of aluminum shot, 4-6 kg / t of lime and 1-2 kg / t of caustic dolomite are added along with a steel current to quickly form a primary slag smelting layer in the ladle refining furnace; after the ladle refining furnace receives a ladle and sends electricity, 5-15 kg / t of fluorite is added in molten steel, and silicon carbide and carbon powder with a ratio of 2: 1-4: 1 are quickly added to perform deoxidation slagging of the molten steel; and then, a molten steel viscosity and alkalinity adjusting agent is added, so that the molten steel forms a pentabasic foam slag system CaO-MgO-SiO2-Al2O3-CaF2 with quaternary alkalinity of 2.0-3.0. The pentabasic foam slag system can effectively prevent mass transfer of nitrogen between semi-high-speed steel and a gas phase, stably isolates air, reduces inspiration, reduces nitrogen in semi-high-speed molten steel, reduces the probability of TiN or Ti(CN) inclusion formation, and prolongs the fatigue life of the semi-high-speed steel hot-rolled aluminum working roller product.

Description

technical field [0001] The invention relates to a method for smelting semi-high-speed steel hot-rolled aluminum work rolls, and belongs to the technical field of roll manufacturing. Background technique [0002] In the smelting of electric furnaces, we always strive to form foamy slag. The reason is that foamy slag has a high reaction ability, which is conducive to accelerating the chemical reaction in the furnace. Slag is good for desulfurization and deoxidation; in addition, after the slag foams, the arc is easy to stabilize, and it can be submerged in the foaming slag for combustion. Most of the heat of the arc is used to heat molten steel and slag, and will not be reflected to the furnace body. Foam slag is beneficial to heating the molten pool and protecting the furnace body. [0003] During the refining process of semi-high-speed steel hot-rolled aluminum work rolls, due to operational reasons, good foam slag cannot be formed. Due to the lack of foam slag, nitrogen is...

AI Technical Summary

Problems solved by technology

[0004] To reduce TiN or Ti(CN) inclusions in molten steel, one is to reduce nitrogen in molten steel, and the other is to reduce Ti in molten steel, but the latter will reduce Ti in molten steel to a lower level, and it will cost a lot. The price is too high, the reason is that the content of titanium in the earth's crust is quite large, the abundance occupies the seventh place, with 0.42%, which is larger than the commonly used metals such as zinc, copper, tin, etc., even larger than chlorine and phosphorus, and Titanium has a very strong combination ability at high temperature, and can combine with oxygen, carbon, nitrogen and many other elements. Therefore, under the current operating conditions, if you want to reduce Ti in molten steel, you can only use expensive iron alloys with low Ti content in the refining process. Adding people to the furnace can achieve the goal, the cost is too high

[0005] Therefore, we can only reduce the nitrogen in the molten steel as much as possible. Since the nitrogen in the semi-high-speed molten steel is in an unsaturated dissolved state, the dissolved amount itself is limited, and nitrogen is also different from oxygen or hydrogen, which can be removed by vacuum refining furnace (VD). So it is very difficult to remove nitrogen from molten steel