A series of Al based alloys with low titanium contents (mass fraction) from 0.178% to 0.526% were directly produced in ordinary industrial electrolyzer. The electrolyzing results show that producing Al based alloys wi...A series of Al based alloys with low titanium contents (mass fraction) from 0.178% to 0.526% were directly produced in ordinary industrial electrolyzer. The electrolyzing results show that producing Al based alloys with titanium contents of less than 0.30% without great loss of electrolysis efficiency is possible. The quantitative analysis shows that this method has a great refining effect on transiting the coarse columnar grains in pure Al to equiaxed grains. The grain sizes decrease with the increase of titanium content and tend to a low limit at about 130 μm. During the solidification, the non equilibrium distribution of titanium leads to a great growth restricting effect and a constitutional under cooling zone in front of the growing liquid /solid interface.展开更多
Titanium is the impurity in some special steel grades.The existence of titanium decreases the grain size,depresses the yield strength,and results in the low quality of these steels in various properties.Thus,titanium ...Titanium is the impurity in some special steel grades.The existence of titanium decreases the grain size,depresses the yield strength,and results in the low quality of these steels in various properties.Thus,titanium should be removed to the minimum.Based on the industrial production of ultra low carbon Al-Si killed steel,the physical-chemical behavior of titanium was investigated in vacuum degassing refining(RH)process with and without desulfurization.The influences of titanium content in hot metal,ladle slag composition,and ladle slag quantity,etc,on titanium content of refined liquid steel were discussed.The results showed that the partition ratio of titanium between ladle slag and liquid steel is in inverse proportion to the 4/3square of aluminum content.The maximum partition ratio of titanium between top slag and liquid steel can be obtained by adjusting an optimum slag composition including contents of FeOxand Al2O3and the slag basicity,and the suitable range of them should be controlled higher than 6%,less than 20%,and within 1.5to 3.0,respectively.Moreover,desulfurization refining by RH decreases the partition ratio of titanium between ladle slag and liquid steel significantly.To ensure the titanium content stably less than 15×10-6 in a 300tladle,the titanium content in hot metal must be less than 500×10-6 and the thickness of basic oxygen furnace(BOF)slag carrying over must be less than 50mm.展开更多
The low-cycle fatigue (LCF) behavior of two kinds of A356 alloys produced by different titanium alloying methods was investigated and compared. The effect of titanium content and titanium alloying methods on LCF behav...The low-cycle fatigue (LCF) behavior of two kinds of A356 alloys produced by different titanium alloying methods was investigated and compared. The effect of titanium content and titanium alloying methods on LCF behavior is analyzed with plastic strain energy density. The results show that all alloys exhibit the cyclic hardening behavior. Raising Ti content can obviously increase the cyclic hardening ability. But the effect of Ti alloying method isn't distinct. Whether for the EA356 alloys or for MA356 alloys, the alloys with low titanium content have longer low-cycle fatigue life than that of the alloys with high titanium content. This is because that the alloys with low titanium content can consume higher cyclic plastic strain energy during cyclic deformation compared with alloys with high titanium content.展开更多
An efficient synthesis of 2, 3-disubstituted indole derivatives through low-valent titanium induced reductive cyclization of acylamido carbonyl compounds is described.
A low-cost β type Ti-1.5Fe-6.8Mo-4.8Al-1.2Nd (mass fraction, %)(T12LCC) alloy was produced by blended elemental powder metallurgy(P/M) method and subsequent thermomechanical treatment. Low cycle fatigue(LCF) behavior...A low-cost β type Ti-1.5Fe-6.8Mo-4.8Al-1.2Nd (mass fraction, %)(T12LCC) alloy was produced by blended elemental powder metallurgy(P/M) method and subsequent thermomechanical treatment. Low cycle fatigue(LCF) behavior of P/M T12LCC alloy before and after thermomechanical treatment was studied. The results show that the LCF resistance of P/M titanium alloy is significantly enhanced through the thermomechanical treatment. The mechanisms for the improvement of LCF behavior are attributed to the elimination of residual pores, the microstructure refining and homogenization.展开更多
The low cycle fatigue(LCF) tests were carried out using symmetrical cyclic loading under total strain amplitude control conditions.The present paper is devoted to investigating the cyclic deformation response of Ti...The low cycle fatigue(LCF) tests were carried out using symmetrical cyclic loading under total strain amplitude control conditions.The present paper is devoted to investigating the cyclic deformation response of Ti–6Al–4V titanium and the electron-beam-welded(EBW) joint in the following aspects,i.e.,cyclic deformation behavior,fatigue life and fatigue fracture behavior.The results show that the softening of the joint is significant at larger strain ranges,while not obvious at smaller strain ranges.The joint shows shorter fatigue life at larger strain ranges and equivalent fatigue life at smaller strain ranges compared with Ti–6Al–4V base metal.A fatigue crack of the joint not only originates at the surface or subsurface,but also at defects in the fusion zone(FZ).The crack propagation zone of Ti–6Al–4V base metal shows ductile fracture mechanism,while the joint shows brittle fracture mechanism.In all the fatigue fracture zones many dimples appear,showing the typical ductile fracture.展开更多
The influences of strain amplitude ranges and dwell time at peak strains on the low cycle fatigue (LCF) properties at 600℃ of a new near α high temperature titanium alloy containing rare earth Nd are investigated. ...The influences of strain amplitude ranges and dwell time at peak strains on the low cycle fatigue (LCF) properties at 600℃ of a new near α high temperature titanium alloy containing rare earth Nd are investigated. The creep fatigue interaction behavior is discussed in this paper in terms of a creep fatigue interaction cumulative law and fatigue crack propagation model. The results show that the creep fatigue interaction is largely dependent on the strain amplitude range, and the tensile dwell periods, as well as compressive dwell periods, have a great influence on the LCF life of this alloy.展开更多
Titanium and its alloys have been widely used for biomedical applications due to their better biomechanical and biochemical compatibility than other metallic materials such as stainless steels and Co-based alloys.A br...Titanium and its alloys have been widely used for biomedical applications due to their better biomechanical and biochemical compatibility than other metallic materials such as stainless steels and Co-based alloys.A brief review on the development of the b-type titanium alloys with high strength and low elastic modulus is given and the use of additive manufacturing technologies to produce porous titanium alloy parts,using Ti-6Al-4V as a reference,and its potential in fabricating biomedica replacements are discussed in this paper.展开更多
Interface morphology has important influence on the bond quality of titanium clad steel plates. The mechanical properties of titanium clad steel plates with wavy and straight interfaces were investigated by tensile-sh...Interface morphology has important influence on the bond quality of titanium clad steel plates. The mechanical properties of titanium clad steel plates with wavy and straight interfaces were investigated by tensile-shear tests and bending tests. The interface morphology of the plates was examined by optical microscopy (OM) and scanning electron microscopy (SEM). The experimental results show that the shear strength of a wavy interface is higher than that of a straight interface. A wavy interface is the guarantee for obtaining high shear strength to provide a greater shear resistance. During the maerobending process, cracks appear in the swirl of the wave tip and ferrotitanium intermetallies. For in-situ observing the bending process by SEM, the wave tip of a wavy interface and the massive ferrotitartium intermetallies of a straight interface are places where cracks initiate and propagate. The results are the same as those observed in the macrobending process. Became of high hardness, the wave tip and the massive ferrotitanium intermetallies are hard in terms of compatible deformation.展开更多
Population density function (PDF), which can eliminate the arbitrariness caused by the choice of the num- ber and the size of bins compared to the well-used histograms, was introduced to analyze the amount of inclus...Population density function (PDF), which can eliminate the arbitrariness caused by the choice of the num- ber and the size of bins compared to the well-used histograms, was introduced to analyze the amount of inclusions. The population evolution of oxide inclusions in forms of PDF in Ti-stabilized ultra-low carbon steels after deoxidation during industrial RH refining and continuous casting processes was analyzed using an automated SEM-EDS system. It was found that after deoxidation till the early stage of casting, the alumina inclusions exhibited a lognormal PDF distribution, and three factors including the existence of a large amount of alumina clusters, the generation of alumi- na from the reduction of Al-Ti-O inclusions and the reoxidation of molten steel were estimated as the reasons. The shape parameter σ was high after deoxidation and then decreased after Ti treatment, indicating that in a short period after deoxidation, the size of alumina inclusions was widely distributed. After Ti treatment, the distribution of inclu- sion size was more concentrated. The scale parameter m decreased with time during the whole refining process, indi- cating that the proportion of large inclusions decreased during refining. Contrarily, the Al-Ti-O inclusions presented a fractal PDF distribution except at the end of casting with fractal dimension D of 4.3, and the constant of propor- tionality C decreased with time during RH refining and increased during casting process. The reoxidation of steel by slag entrapped from ladle was considered as the reason for the lognormal PDF behavior of Al-Ti-O inclusions at the end of casting.展开更多
The nanocrystalline TiO_2 powder were prepared by improved sol-gel method at low temperature under ambient pressure. The prepared TiO_2 powder was characterized by X-ray diffraction (XRD), transmission electron micros...The nanocrystalline TiO_2 powder were prepared by improved sol-gel method at low temperature under ambient pressure. The prepared TiO_2 powder was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM). It is found that the yield of anatase TiO_2 significantly increases with the reduction of pH by increasing the nucleation rate of anatase. There is an optimum amount of water in sol for the formation of anatase by combining two effects on the concentration of Ti(OH)_4 in gels. Increasing in reaction temperature also benefit to the nucleation of anatase of TiO_2.展开更多
The mechanical properties of Ti/APC-2/Kevlar/epoxy hybrid composite laminates after low velocity impact were investigated at room temperature. There were three types of samples, including three layered [Ti/(0/90)s/Ti]...The mechanical properties of Ti/APC-2/Kevlar/epoxy hybrid composite laminates after low velocity impact were investigated at room temperature. There were three types of samples, including three layered [Ti/(0/90)s/Ti], five layered [Ti/(0/90)2/]s and nine layered [Ti/Kevlar/Ti/(0/90)2/]s. The lay-ups of APC-2 were crossply, while Ti layers were treated by chromic acid anodic method. Ti and APC-2 were stacked to fabricate the composite laminates via hot press curing process. Kevlar layers were added to fabricate nine-layered composite laminates via vacuum assisted resin transfer molding. The drop-weight tests were conducted with a hemispherical nosed projectile in 10 mm diameter. The impact loads were 5 kg and 10 kg and impact heights were adjusted to penetrate samples or the maximum height 1.50 m. The static tensile tests were conducted to measure the residual mechanical properties after impact. The free body drop tests were also simulated by using finite element method and software ANSYS LS-DYNA3D. The results showed that the bottom Ti layer absorbed more internal energy than the top Ti layer, then the cracks were found in the bottom Ti layer more often. The ultimate tensile strength reduced significantly after impact. The initial longitudinal compliance increased with the impact height increasing and decreased after the samples penetrated. Comparing the experimental data with the numerical results, it was found that the damage of the latter was more serious than that of the former. On the conservative side, the results of numerical simulation are acceptable and adopted for applications when no testing data available.展开更多
: Titanium is an impurity element in some special steel grades. The existence of titanium decreases the grain size and lowers the yield strength ,resulting in low quality of these steels with regard to various proper...: Titanium is an impurity element in some special steel grades. The existence of titanium decreases the grain size and lowers the yield strength ,resulting in low quality of these steels with regard to various properties. Thus, the titanium content should be reduced to the minimum. Based on the industrial production of ultra-low carbon A1-Si killed steel, this paper investigated the physical-chemical behaviors of titanium with and without desulfurization during RH refining. The influences of Ti content in hot metal, ladle slag composition, and ladle slag quantity, etc., on the Ti content in refined liquid steel were discussed. The results show that the partition ratio of titanium between ladle slag and liquid steel is inversely proportional to the AI content to the power of 4/3 ,and the empirical formula regressed from practical experience can be expressed as w(TiO2)/WTi=48/w[AI]4/3 Maximum partition ratio of titanium between top slag and liquid steel can be ensured W[Til WIAIIby an optimum slag composition including components of FeOx and A12 03 and an appropriate slag basicity. The contents of FetO and A1203 should be controlled above 6% and below 20% respectively and the slag basicity should be kept within 1.5 to 3.0. Moreover, desulfurization refining in the RH vacuum will decrease the partition ratio of titanium between ladle slag and liquid steel significantly. To keep the Ti content stably below 15 ×10 ^-4% in a 300 ton ladle ,the Ti content in hot metal must be lower than 500 × 10^-4% and the thickness of ladle slag carried over from BOF slag must be less than 50 ram.展开更多
An induction levitation melting (ILM) refining process is performed to remove most microsized inclusions in ultra-low carbon steel (UCS). Nanosized, spheroid shaped sulfide precipitates remain dispersed in the UCS...An induction levitation melting (ILM) refining process is performed to remove most microsized inclusions in ultra-low carbon steel (UCS). Nanosized, spheroid shaped sulfide precipitates remain dispersed in the UCS. During the ILM process, the UCS is molten and is rotated under an upward magnetic field. With the addition of Ti additives, the spinning molten steel under the upward magnetic field ejects particles because of resultant centrifugal, floating, and magnetic forces. Magnetic force plays a key role in removing sub-micrometer-sized particles, composed of porous aluminum titanate enwrapping alumina nuclei. Consequently, sulfide precipitates with sizes less than 50 nan remain dispersed in the steel matrix. These findings open a path to the fabrication of clean steel or steel bearing only a nanosized strengthen- ing phase.展开更多
文摘A series of Al based alloys with low titanium contents (mass fraction) from 0.178% to 0.526% were directly produced in ordinary industrial electrolyzer. The electrolyzing results show that producing Al based alloys with titanium contents of less than 0.30% without great loss of electrolysis efficiency is possible. The quantitative analysis shows that this method has a great refining effect on transiting the coarse columnar grains in pure Al to equiaxed grains. The grain sizes decrease with the increase of titanium content and tend to a low limit at about 130 μm. During the solidification, the non equilibrium distribution of titanium leads to a great growth restricting effect and a constitutional under cooling zone in front of the growing liquid /solid interface.
基金Sponsored by National Natural Science Foundation of China(51104109)
文摘Titanium is the impurity in some special steel grades.The existence of titanium decreases the grain size,depresses the yield strength,and results in the low quality of these steels in various properties.Thus,titanium should be removed to the minimum.Based on the industrial production of ultra low carbon Al-Si killed steel,the physical-chemical behavior of titanium was investigated in vacuum degassing refining(RH)process with and without desulfurization.The influences of titanium content in hot metal,ladle slag composition,and ladle slag quantity,etc,on titanium content of refined liquid steel were discussed.The results showed that the partition ratio of titanium between ladle slag and liquid steel is in inverse proportion to the 4/3square of aluminum content.The maximum partition ratio of titanium between top slag and liquid steel can be obtained by adjusting an optimum slag composition including contents of FeOxand Al2O3and the slag basicity,and the suitable range of them should be controlled higher than 6%,less than 20%,and within 1.5to 3.0,respectively.Moreover,desulfurization refining by RH decreases the partition ratio of titanium between ladle slag and liquid steel significantly.To ensure the titanium content stably less than 15×10-6 in a 300tladle,the titanium content in hot metal must be less than 500×10-6 and the thickness of basic oxygen furnace(BOF)slag carrying over must be less than 50mm.
文摘The low-cycle fatigue (LCF) behavior of two kinds of A356 alloys produced by different titanium alloying methods was investigated and compared. The effect of titanium content and titanium alloying methods on LCF behavior is analyzed with plastic strain energy density. The results show that all alloys exhibit the cyclic hardening behavior. Raising Ti content can obviously increase the cyclic hardening ability. But the effect of Ti alloying method isn't distinct. Whether for the EA356 alloys or for MA356 alloys, the alloys with low titanium content have longer low-cycle fatigue life than that of the alloys with high titanium content. This is because that the alloys with low titanium content can consume higher cyclic plastic strain energy during cyclic deformation compared with alloys with high titanium content.
文摘An efficient synthesis of 2, 3-disubstituted indole derivatives through low-valent titanium induced reductive cyclization of acylamido carbonyl compounds is described.
基金Project(2001AA332010) supported by the National Advanced Materials Committee of China
文摘A low-cost β type Ti-1.5Fe-6.8Mo-4.8Al-1.2Nd (mass fraction, %)(T12LCC) alloy was produced by blended elemental powder metallurgy(P/M) method and subsequent thermomechanical treatment. Low cycle fatigue(LCF) behavior of P/M T12LCC alloy before and after thermomechanical treatment was studied. The results show that the LCF resistance of P/M titanium alloy is significantly enhanced through the thermomechanical treatment. The mechanisms for the improvement of LCF behavior are attributed to the elimination of residual pores, the microstructure refining and homogenization.
基金financially supported by the HiTech Research and Development Program of China(No.2012AA052102)the Program of International Science Technology Cooperation of China(No.2013DFA61590)
文摘The low cycle fatigue(LCF) tests were carried out using symmetrical cyclic loading under total strain amplitude control conditions.The present paper is devoted to investigating the cyclic deformation response of Ti–6Al–4V titanium and the electron-beam-welded(EBW) joint in the following aspects,i.e.,cyclic deformation behavior,fatigue life and fatigue fracture behavior.The results show that the softening of the joint is significant at larger strain ranges,while not obvious at smaller strain ranges.The joint shows shorter fatigue life at larger strain ranges and equivalent fatigue life at smaller strain ranges compared with Ti–6Al–4V base metal.A fatigue crack of the joint not only originates at the surface or subsurface,but also at defects in the fusion zone(FZ).The crack propagation zone of Ti–6Al–4V base metal shows ductile fracture mechanism,while the joint shows brittle fracture mechanism.In all the fatigue fracture zones many dimples appear,showing the typical ductile fracture.
文摘The influences of strain amplitude ranges and dwell time at peak strains on the low cycle fatigue (LCF) properties at 600℃ of a new near α high temperature titanium alloy containing rare earth Nd are investigated. The creep fatigue interaction behavior is discussed in this paper in terms of a creep fatigue interaction cumulative law and fatigue crack propagation model. The results show that the creep fatigue interaction is largely dependent on the strain amplitude range, and the tensile dwell periods, as well as compressive dwell periods, have a great influence on the LCF life of this alloy.
基金financially supported by the National High Technology Research and Development Program of China (No.2015AA033702)the National Basic Research Program of China (Nos.2012CB619103 and 2012CB933901)the National Natural Science Foundation of China (Nos.51271180 and 51271182)
文摘Titanium and its alloys have been widely used for biomedical applications due to their better biomechanical and biochemical compatibility than other metallic materials such as stainless steels and Co-based alloys.A brief review on the development of the b-type titanium alloys with high strength and low elastic modulus is given and the use of additive manufacturing technologies to produce porous titanium alloy parts,using Ti-6Al-4V as a reference,and its potential in fabricating biomedica replacements are discussed in this paper.
文摘Interface morphology has important influence on the bond quality of titanium clad steel plates. The mechanical properties of titanium clad steel plates with wavy and straight interfaces were investigated by tensile-shear tests and bending tests. The interface morphology of the plates was examined by optical microscopy (OM) and scanning electron microscopy (SEM). The experimental results show that the shear strength of a wavy interface is higher than that of a straight interface. A wavy interface is the guarantee for obtaining high shear strength to provide a greater shear resistance. During the maerobending process, cracks appear in the swirl of the wave tip and ferrotitanium intermetallies. For in-situ observing the bending process by SEM, the wave tip of a wavy interface and the massive ferrotitartium intermetallies of a straight interface are places where cracks initiate and propagate. The results are the same as those observed in the macrobending process. Became of high hardness, the wave tip and the massive ferrotitanium intermetallies are hard in terms of compatible deformation.
基金Item Sponsored by National Natural Science Foundation of China(51274034,51334002,51404019)Independent Research and Development Program from State Key Laboratory of Advanced Metallurgy of China
文摘Population density function (PDF), which can eliminate the arbitrariness caused by the choice of the num- ber and the size of bins compared to the well-used histograms, was introduced to analyze the amount of inclusions. The population evolution of oxide inclusions in forms of PDF in Ti-stabilized ultra-low carbon steels after deoxidation during industrial RH refining and continuous casting processes was analyzed using an automated SEM-EDS system. It was found that after deoxidation till the early stage of casting, the alumina inclusions exhibited a lognormal PDF distribution, and three factors including the existence of a large amount of alumina clusters, the generation of alumi- na from the reduction of Al-Ti-O inclusions and the reoxidation of molten steel were estimated as the reasons. The shape parameter σ was high after deoxidation and then decreased after Ti treatment, indicating that in a short period after deoxidation, the size of alumina inclusions was widely distributed. After Ti treatment, the distribution of inclu- sion size was more concentrated. The scale parameter m decreased with time during the whole refining process, indi- cating that the proportion of large inclusions decreased during refining. Contrarily, the Al-Ti-O inclusions presented a fractal PDF distribution except at the end of casting with fractal dimension D of 4.3, and the constant of propor- tionality C decreased with time during RH refining and increased during casting process. The reoxidation of steel by slag entrapped from ladle was considered as the reason for the lognormal PDF behavior of Al-Ti-O inclusions at the end of casting.
文摘The nanocrystalline TiO_2 powder were prepared by improved sol-gel method at low temperature under ambient pressure. The prepared TiO_2 powder was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM). It is found that the yield of anatase TiO_2 significantly increases with the reduction of pH by increasing the nucleation rate of anatase. There is an optimum amount of water in sol for the formation of anatase by combining two effects on the concentration of Ti(OH)_4 in gels. Increasing in reaction temperature also benefit to the nucleation of anatase of TiO_2.
文摘The mechanical properties of Ti/APC-2/Kevlar/epoxy hybrid composite laminates after low velocity impact were investigated at room temperature. There were three types of samples, including three layered [Ti/(0/90)s/Ti], five layered [Ti/(0/90)2/]s and nine layered [Ti/Kevlar/Ti/(0/90)2/]s. The lay-ups of APC-2 were crossply, while Ti layers were treated by chromic acid anodic method. Ti and APC-2 were stacked to fabricate the composite laminates via hot press curing process. Kevlar layers were added to fabricate nine-layered composite laminates via vacuum assisted resin transfer molding. The drop-weight tests were conducted with a hemispherical nosed projectile in 10 mm diameter. The impact loads were 5 kg and 10 kg and impact heights were adjusted to penetrate samples or the maximum height 1.50 m. The static tensile tests were conducted to measure the residual mechanical properties after impact. The free body drop tests were also simulated by using finite element method and software ANSYS LS-DYNA3D. The results showed that the bottom Ti layer absorbed more internal energy than the top Ti layer, then the cracks were found in the bottom Ti layer more often. The ultimate tensile strength reduced significantly after impact. The initial longitudinal compliance increased with the impact height increasing and decreased after the samples penetrated. Comparing the experimental data with the numerical results, it was found that the damage of the latter was more serious than that of the former. On the conservative side, the results of numerical simulation are acceptable and adopted for applications when no testing data available.
文摘: Titanium is an impurity element in some special steel grades. The existence of titanium decreases the grain size and lowers the yield strength ,resulting in low quality of these steels with regard to various properties. Thus, the titanium content should be reduced to the minimum. Based on the industrial production of ultra-low carbon A1-Si killed steel, this paper investigated the physical-chemical behaviors of titanium with and without desulfurization during RH refining. The influences of Ti content in hot metal, ladle slag composition, and ladle slag quantity, etc., on the Ti content in refined liquid steel were discussed. The results show that the partition ratio of titanium between ladle slag and liquid steel is inversely proportional to the AI content to the power of 4/3 ,and the empirical formula regressed from practical experience can be expressed as w(TiO2)/WTi=48/w[AI]4/3 Maximum partition ratio of titanium between top slag and liquid steel can be ensured W[Til WIAIIby an optimum slag composition including components of FeOx and A12 03 and an appropriate slag basicity. The contents of FetO and A1203 should be controlled above 6% and below 20% respectively and the slag basicity should be kept within 1.5 to 3.0. Moreover, desulfurization refining in the RH vacuum will decrease the partition ratio of titanium between ladle slag and liquid steel significantly. To keep the Ti content stably below 15 ×10 ^-4% in a 300 ton ladle ,the Ti content in hot metal must be lower than 500 × 10^-4% and the thickness of ladle slag carried over from BOF slag must be less than 50 ram.
基金supported partly by the National Natural Science Foundation of China (No. 51472170)the Major State Basic Research Development Program of China (No. 2011CB932700)
文摘An induction levitation melting (ILM) refining process is performed to remove most microsized inclusions in ultra-low carbon steel (UCS). Nanosized, spheroid shaped sulfide precipitates remain dispersed in the UCS. During the ILM process, the UCS is molten and is rotated under an upward magnetic field. With the addition of Ti additives, the spinning molten steel under the upward magnetic field ejects particles because of resultant centrifugal, floating, and magnetic forces. Magnetic force plays a key role in removing sub-micrometer-sized particles, composed of porous aluminum titanate enwrapping alumina nuclei. Consequently, sulfide precipitates with sizes less than 50 nan remain dispersed in the steel matrix. These findings open a path to the fabrication of clean steel or steel bearing only a nanosized strengthen- ing phase.