| Steel industry has always been the mainstay industry of the development of the nationaleconomy. With the rapid development of modern industry, such as pillar industries, metallurgy,electric power, shipbuilding, pressure vessels, etc, even their complex service environment,makes it extremely harsh to control the ingredients of sulfur, oxygen content and othermicro-alloying elements in the steel. Ladle argon blowing feed line technology,by feeding thelinear calcium, rare earth, aluminum or other trace elements into the ladle, can effectivelyachieve the molten steel desulfurization, the deoxy purification and control the micro-alloycomposition. It has been widely used in ladle refining process outside the furnace. However,after feed the ladle the metal core wire, it has a extremely complex behavior of contactconvective heat transfer with the liquid steel. So it’s difficult to accurately calculate themelting time of the core wire. The yield, generated by blowing argon in the effects ofgas-liquid two-phase flow coupling after feed ladle cored wire, and the problem using powerstirring to make it homogenized need to be addressed and solved.Taking160t steel ladle with bottom blowing argon feed line process of a factory as theresearch object and using the FLUENT software platform, a core spun yarn feedinggasification model and steel ladle blowing argon CFD model which is a gas-liquid two phaseand unsteady can be established. Then do a deep research on the influence law how someparameters such as the wire feed position, gasification critical depth and speed of argonblowing affact the feeding metal content in liquid steel and the feeding metal distributionuniformity. In order to solve the transient temperature field in the process of steel ladlefeeding with metal core spun yarn, it needs to consider the heat transfer boundary on thedynamic contact between core spun yarn and the flowing liquid steel.On the basis of theMSC. MARC secondary development modeling, it is able to conduct a tracking simulation onthe temperature of every point within core and do a research on the influence law of thethickness of steel cladding in the core spun yarn surface and core spun yarn diameter on thecritical melting time,which can provide theoretical basis about core spun yarnspecifications optimization and feeding technological parameters optimization.The simulative and analytical results show that the steel flow field comes into being circulation after the argon enters into steel ladle.It can stir the liquid steel, which caneffectively promote the wire gas distributing more homogeneous in steel liquid.Whenquantity of blowing argon flow reaches8m3/h, metal gas distributes best and it takes about450seconds. In the condition of2.5m/s as feeding speed and3m as feeding depth, thepercentage of gas volume in liquid steel over0.05%has reached95%. In this conditioncalcium content and distribution can meet the requirements of calcium treatment such asdesulfurization and deoxidizing. When Core spun yarn goes deep into3m, metal gas yieldreaches maximum. Simulative results about Calcium core temperature field show that in themoment the calcium iron wire and liquid steel contact each other, the part liquid steeltouching with core wire surface was rapidly cooling to750℃.Because this temperature islower than steel melting point, it take shape into steel shell of thickness about4mm.With theheat conducting inward, calcium core firstly reaches its gasification temperature, and thensteel strip can be completely melted. If steel strip thickness increases by0.1mm, calcium ironwire melting time will increase0.1second. Combining with the results of flow field analysis,we can know melting speed of the calcium iron wire is appropriate when its diameter isbetween12mm~15mm. |
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