Cored Wire is mainly used in steelmaking, it can purify the shape of steel inclusions, make pure molten steel and partly change the nature and shape of inclusions. It can also prevent nozzle clogging during casting and reduce alloy consumption.
The powder additive package is pulverized into a certain size, wrapped in a narrow strip of continuous formation and then wound into coils. The silicon calcium alloy is then inserted into the ladle through the wire feeder, and melts at an ideal depth.
Steelmaking processes are typically limited by the rate at which metallurgy additives enter the liquid metal. This limit is imposed by diffusion through a quasi-static boundary layer that forms almost instantaneously when an injected material first touches the liquid metal.
To overcome this limitation, some manufacturers have tried injecting metallic calcium deep into the liquid metal. The injection technique is based upon the assumption that ferrostatic pressure can sufficiently suppress boiling of the metallic calcium in order to allow it to penetrate to the molten steel bath.
However, the vapor and boiling action of the metallic calcium in the molten metal largely prevents it from reaching this penetration depth. Furthermore, the chemical reaction of metallic calcium with molten steel would produce brittle aluminates that are more deleterious than low-melting, non-deformable inclusions made of soluble oxides. To overcome this difficulty, a more effective method of adding calcium is required.
The deoxidizing effect of calcium is greatly increased when it is injected into molten steel through cored wire. The cored wire is fed into the molten steel at a proper rate so that it enters the molten steel at an optimal depth close to the ladle bottom. This can make the contact between the Ca vapor and molten steel as intimate as possible for a long time, which helps to modify hard alumina inclusions into soft calcium aluminates.
Because calcium metal has a high affinity with oxygen, it can be used as an ideal deoxidizer and desulfurizing agent in industrial steel making. It also has the advantage of improving the quality of molten steel, especially in continuous casting of aluminum-killed molten steel. It can change the shape of inclusions, improve castability and prevent nozzle nodulation in continuous casting steel. It can also reduce the oxidation burning loss rate, shorten the smelting time and precisely control the composition of molten steel.
Inclusions in molten steel can affect the quality of the final product. Silicon calcium alloy can be used to change the shape of inclusions, allowing the metal to better adhere to the melted steel. It can also improve the castability of the steel, which will result in fewer defects and a more uniform finished product.
The addition of calcium through cored wire is a popular way to increase the yield of calcium. However, it is important to choose the correct type of cored wire for each job. For example, using a copper cored wire for a high-strength steel can cause arc blowout. In addition, the high temperature of the cored wire can cause an abnormal coarsening of the welded area.
To avoid this problem, it is best to use a calcium cored wire with a low melting point and an adequate reactivity. This will ensure that the cored wire melts into the molten steel at an optimal depth. This will increase the yield of the added element and prevent the reaction of the element with air or slag.
Using the cored wire method, the metallurgy additives can be fed into the molten steel at a fixed speed and absorbed at the bottom of the ladle. This is an effective method for molten steel deoxidation, desulfurization, alloy fine-tuning and control of the shape of inclusions. It can also help increase the yield of calcium, improve the quality of cast iron and reduce the cost of steel casting.
The feeding position has a great influence on the yield of calcium. The feeding position should be chosen at the center of the molten steel flow, away from the argon blowing circle. This will prevent the vaporization of calcium and ensure that it enters the liquid steel in a solid state and is not reacted with oxygen or sulfur.
The feeding speed is also important. If the feed speed is too fast, it will cause calcium to be burned by slag and air. It can also cause the feeding depth to be insufficient, which will result in low calcium absorption.
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