The Quality Specifications of Mischmetal Wire and Rod and the Method of Adding Rare Earth in Steel

ＴｈｅＱｕａｌｉｔｙＳｐｅｃｉｆｉｃａｔｉｏｎｓｏｆＭｉｓｃｈｍｅｔａｌＷｉｒｅａｎｄＲｏｄａｎｄｔｈｅＭｅｔｈｏｄｏｆＡｄｄｉｎｇＲａｒｅＥａｒｔｈｉｎＳｔｅｅｌ￥ＪｕＹｕａｎ－Ｆｅｎｇ；ＺｕｏＳｈｅｎｇ－Ｈｕａ（ＨｕｂｅｉＣｒｙｓｔａｌｉｎｅＳｉ...     

Behavior of Liquid Steel in Mold for Thin Slab Caster

Thinslabcasting ,animportantnewtechnologyindevelopmentofironandsteelindustry ,isasignif icantbreakthroughinthefieldofnearnetshapeca stingtechnology .Althoughthethinslabcastinghasbeensuccessfullyappliedtoindustrialproduction ,itisstillexpectedtoimprovefurtherinthetermsofsteelgrades ,qualityandproductivity .Thekeyistomodifytheinternalshapeofmoldandsubmergeden trynozzle (SEN ) .Atpresent ,theinternalshapeofmoldandSENhasbeenfurtherstudiedtocastdif ferentqualitysteelsinChinaandothercountries[1,2…     

Steady State Heat Transfer of Ladle Furnace During Steel Production Process

The heat transfer analysis was performed for an industrial ladle furnace （LF） with a capacity of 55-57 t in Turkey. The heat losses by conduction, convection and radiation from outer and bottom surfaces, top and electrodes of LF were determined in detail. Finally, some suggestions about decreasing heat losses were presented.     

Motion and Detachment Behaviors of Liquid Inclusion at Molten Steel–Slag Interfaces

Metallurgical and Materials Transactions B - The fundamental physics of particles adsorbed at the liquid interfaces has numerous applications in a wide field. In the current study, the motion and...     

Liquid–Solid Reactions and Microstructure of SiC-5120 Steel Composite Brake Material

This study investigated solid–liquid reactions between SiC preform and molten 5120 steel during infiltration casting of SiC-steel composite for heavy duty brake applications. The reactions between SiC and the molten steel resulted in the formation of three distinctive microstructural regions, including the α ₁-Fe(Si)-graphite region, the pearlite region, and the ferrite-pearlite region. The phase structures were identified by means of X-ray diffraction, X-ray energy dispersive spectrometry, and metallographic examination. These observations reveal that SiC was decomposed via reactions with the molten steel. The diffusion of C and Si into the molten steel and selective solidification led to the formation of different regions with varied C and Si contents. The microstructures produced during the solidification sequence are identified to be the ferrite-pearlite → pearlite → α ₁-Fe(Si) + graphite and cementite.     

Prediction of Behavior of Alumina Inclusion in Front of Solid–Liquid Interface in SPFH590 Steel

Metallurgical and Materials Transactions B - To predict the behavior of an alumina inclusion in front of the solid–liquid interface during solidification, the interfacial tension between...     

Liquid steel transfer—the delivery of quality

During recent years, in parallel with developments in high-speed casting, there have been increasing demands for improved steel quality. These demands are being met by advances in our knowledge of the chemical, physical and thermal interactions between steel, gas, slag and refractory phases which take place within individual reactors as well as during transfer operations. Transfer operations must be precisely controlled, otherwise they become destroyers of quality, and quality achieved within one reactor can be lost during transfer to the next.     

Structure of a Carbon Steel–Stainless Steel Bimetal

Bimetallic samples may be produced by casting St3 structural steel between sheets of Kh18N9T stainless steel in a mold, with subsequent hot rolling of the three-layer sheet. Such samples have a structure in which Kh18N9T stainless steel appears at the outer edge on both sides, while the core consists of St3 structural steel. Analysis of the boundary between the steels confirms the absence of defects: it is continuous and of high quality. The microstructure of the junction is investigated by optical, scanning-probe, and electron microscopy. Three structural components are observed from the pearlitic to the austenitic steel: a weakened section of the ferritic layer; a strengthened section of the ferritic layer; and a dark-etching layer at the austenitic steel. The following results are obtained by scanning-probe microscopy—in particular, the constantforce contact method—and optical metallography: on approaching the boundary from the St3 steel, a carbon- free layer with purely ferritic structure is observed, rather than the usual structure for low-carbon steel, which consists of a ferrite matrix with pearlite colonies. On approaching the boundary from the Kh18N9T steel, a carburized layer is observed. In addition, the boundary includes an intermediate carbide layer (depth up to 50 μm). The change in microhardness in the region where the St3 structural steel meets the external layer of Kh18N9T stainless steel indicates considerable increase in strength of the materials. Elemental microanalysis of the St3 steel–Kh18N9T steel boundary reveals the change in concentration of the alloying elements on approaching the boundary. The presence of chromium in St3 steel and the increase in carbon concentration in Kh18N9T stainless steel confirm that two opposing diffusional fluxes are formed: the diffusion of carbon from the St3 steel; and the diffusion of alloying elements from Kh18N9T steel. The resulting carbides explain the increased hardness of both steels close to the boundary.     

Theoretical Investigation on Deoxidation of Liquid Steel for Fe–Al–Si–O System

Deoxidation of liquid steel involves consumption of high energy materials like ferro alloys and generation of deoxidation products which could be entrapped into liquid steel as non-metallic inclusions. The present investigation is focused on deoxidation of liquid steel, considering mainly aluminium and silicon as deoxidizer. A simple and realistic mathematical model of deoxidation of liquid steel has been developed based on the thermodynamic principles and material balance approach for day to day industrial practice. One of the main aims of the theoretical study was to predict the amount of deoxidizers required for a given steel composition. A methodology has also been developed to predict the stability of different oxides expected to be present in liquid steel after deoxidation. Model predictions have been compared with the industrial data as well as results obtained from commercial thermodynamic software package FactSage 6.4, simulated under identical conditions. Model predictions are in reasonable agreement with the ferro alloy consumption in industrial steelmaking processes.     

The Influence of Mischmetal on Wetting of Steel by Zn+5wt%Al Alloys

The wetting of steel sheet by liquid Zn+5 wt%Al alloy has been measured by the Meniscograph.The result shows that the addition of mischmetal in Zn+5 wt%Al alloy decreases the surface tension of thealloy,reduces the wetting angle of the liquid alloy raising in steel substrate surface and enhances the adhesivepower and wettability between them.It is concluded that the mischmetal addition in baths influences the reac-tion between steel sheet and liquid Zn+5 wt%Al alloy and thus improves the wettability of them.     

ABSTRACTS——FromJournal of Iron and Steel Research(in Chinese)

2006 ,18(7)—2006 ,18(8)Technology and Application of Comprehensively Trea-ting Electric Arc Furnace DustLU Hai-bo ,YUANShou-qian ( The School of Met-allurgical Engineering, Xi′an University of Ar-chitecture and Technology, Xi′an 710055 , Shanxi ,China)Abstract :Based on the comprehensive treat ment and utilizationof the dust of electric arc furnace , the foreign technologymeasures of treating the dust of electric arc furnace are intro-duced . Principles of pyrogenic process , wet …     

Effect of Top Slag Basicity on Quality of Steel Treated by Exothermic Agent SiFe and SiCaBa during Chemical Heating

Ｔｈｅｃｈｅｍｉｃａｌｈｅａｔｉｎｇａｓａｋｉｎｄｏｆｈｅａｔｉｎｇｍｅｔｈｏｄｆｏｒｌａｄｌｅｒｅｆｉｎｉｎｇｉｓｐａｉｄｍｏｒｅａｎｄｍｏｒｅａｔ ｔｅｎｔｉｏｎ ,ｓｕｃｈａｓｉｎＲＨ ＫＴＢ ,ＣＡＳ ＯＢ ( ＰＩ) ,ＲＨ ＯＢ[1- 4] ｅｔｃ .Ａｍｏｎｇｔｈｅｍ ,ｔｈｅＣＡＳ ＯＢｐｒｏｃｅｓｓｄｅ ｖｅｌｏｐｅｄｒａｐｉｄｌｙｄｕｅｔｏｉｔｓａｂｉｌｉｔｙｏｆｒａｐｉｄｌｙｒａｉｓｉｎｇｔｅｍｐｅｒａｔｕｒｅａｎｄａｃｃｕｒａｔｅｌｙａｄｊｕｓｔｉｎｇｓｔｅｅｌｃｏｍｐｏｓｉ ｔｉｏｎ .Ｂｕｔｔｈｅ…     

Liquid Mixing in Thick-Slag-Covered Metallurgical Baths—Blending of Bath

Liquid mixing in bottom-blown, gas-stirred reactors has a significant impact on process efficiency and product quality. Cold physical models were used to simulate liquid bath mixing behavior covered with a thick slag layer. The dependence of blending time on specific energy input rate, slag height, and physical properties of metal and slag was studied. A new parameter, called the “effective bath height,” is defined as a function of the slag and metal thicknesses and their relative densities to develop a unified correlation for blending time of slag-covered baths and baths without slags. Furthermore, energy dissipation associated with an increase in interfacial area was evaluated.     

New Application of Stainless Steel

Several rigid substrates such as stainless steel, titanium alloy, aluminum alloy, nickel foil, silicon, and sodium lime glass have been employed for manufacturing high quality TiO2 films by metal organic chemical vapor deposition （MOCVD）. The as-deposited TiO2 films have been characterized with SEM/EDX and XRD. The photocatalytic properties were investigated by decomposition of aqueous orange Ⅱ. UV VIS photospectrometer was employed to check the absorption characteristics and photocatalytic degradation activity. The results show that films synthesized on metal substrates display higher photoactivities than that on absolute substrates such as silicon and glass. It is found that solar light is an alternative to UV-light used for illumination during photodegradation of orange Ⅱ. TiO2 film on stainless steel substrate was regarded as the best one for photocatalysis.