Incorporation of calcium silicon cored wire into molten steel can improve the adding efficiency of metal calcium, reduce consumption of the high energy-consuming resultant product and enhance quality of casting products.
The proper feeding position is of great significance for the calcium addition process. If the feeding speed is too fast, the solid calcium will not be fed deep into the molten steel and will float up to the surface before it can be consumed.
Calcium cored wire is used to feed metal calcium into molten steel to improve the quality of steel. It can effectively deoxidize, desulfurize and reduce the quantity of non-metallic inclusions. It can also solve the problem of nozzle blockage caused by calcium lumps.
A typical modification involves replacing the etching electrolyte with one containing a much lower concentration of HF. This results in a diffusion limited situation that removes the porous Si faster than the pores can propagate. This makes the resulting free-standing porous Si film kinetically inert to further oxidation.
The steel sheath of the calcium cored wire is rolled and stuffed with alloy powders by professional cored wire machine, which ensures that the granules are evenly distributed. The alloy powders can be iron, aluminium or calcium. A monoalkoxydimethylsilane can be more effective than trialkoxysilanes as a surface linker for porous Si, because they bind to silanol sites and are less likely to oligomerize or clog smaller pore openings [107]. The resulting functionalized porous Si is stable to hydroxide solutions at pH>10 and is less susceptible to further oxidation when exposed to air or slag.
A mined product, silica is a form of quartz with a low melting point. Silica is used as a filter material, and has been a mainstay of the steel industry for years. It is used to purify molten iron, and is also a key ingredient in glass.
Previously, calcium was added to the ladle by spraying or adding calcium lumps to the molten steel. However, this method has a high reactivity to the liquid steel and results in many oxidation burning losses.
To solve this problem, a calcium cored wire is introduced. A calcium silicon alloy powder is pressed and stuffed into a steel strip by a professional cored wire machine. Then it is inserted smoothly into the molten iron or molten steel. The cored wire is positioned at an ideal depth to trigger a physicochemical reaction with the added elements and avoid reaction with atmospheric oxygen or the oxides in the ladle slags. This technology greatly improves the element yield and the quality of steel products.
A calcium based deoxidizer is an essential refining technology for the iron and steel industry. It is used to deeply reduce the content of harmful elements in molten steel and make the composition and shape of inclusions change. It is also used to avoid nozzle clogging of cast aluminum killed steel and improve the mechanical properties of steel.
The metal calcium has a great affinity with oxygen and it is easy to oxidize. A large amount of oxidation product can not only reduce the rate of ladle feed process but also seriously affect the effectiveness of calcium treatment.
In order to overcome the shortcomings of traditional calcium cored wire, a new production method is developed. The new method consists of preparing a solid calcium core wire, carrying out surface passivation for the cored wire and coating a thin metal aluminum layer on the outer surface of the solid calcium core wire. This can eliminate the generation of a large quantity of oxycarbide in the process of manufacturing reduced iron powder and can greatly improve the efficiency of calcium treatment.
The calcium silicon cored wire is an important new type of alloy auxiliary equipment for molten steel deoxidation, desulfurization, and alloy fine-tuning. It is easy to use, safe, efficient, and economical. Its operation is convenient, does not generate smoke, the temperature drop is small, and it doesn’t consume refractory materials or carrier gas. It also has the advantages of being simple in structure, small in area, and low in investment.
The utility model is a kind of high efficiency composite cored wire comprising solid pure metal calcium wire rod 1, powder layer 2, and sheet metal coverings 3 that coat the outer surface of the powder layer 2. The passivation of metal calcium line equably prevents the surface of the pure calcium from oxidation, and improves the recovery rate of the pure calcium. It can also reduce the steel slag liquid level fierceness to seethe and splash in the process of feeding the cored wire, which obviously increases the calcium treatment efficiency.
English
Write a Message