Effect of Temperature and Phase Constitution on Kinetics of La Diffusion

The diffusion of La inε－Fe2-3N(ε)andν′-Fe4N(ν′)phases produced by plasma nitriding was studied.It is found that with increasing nitriding time,theεphase continuously decomposes into ν′one under employed experimental condition and compared with ν′phase orε ν′ones,the mono oneεhas an impedient effect on depth of La diffusion,The growth of La layer in dual phases and mono one follows an approximate exponential law and a parabolic one ,respectively,and this kinetics law does not change with increasing temperature,The effect of increasing temperature in the range of 520to560℃on La diffusion depth is less than that of phase constitution change such as the decompostition ofεphase intoν′one.     

Effect of Temperature on Microstructure and Formability of Al-10 mass％ Si Coatings

The type-1aluminized(Al-10mass% Si)coating on hot stamped steel is used in commercial applications.The effect of temperature on microstructure and formability of the Al-10mass% Si coating was investigated.Hot-dip aluminized 22MnB5 steel was heated at 870,900,930,and 1 050 ℃ for 5 min.After heat treatment at different temperatures,the microstructure of Al-10mass% Si was characterized by field-emission scanning electron microscopy and energy-dispersive spectroscopy.The results show that when the Al-10mass% Si coating was heated at 870℃for 5min,three types of intermetallic phases were formed:two ternary Fe-Si-Al phases(Fe2SiAl7+Fe2Si2Al5and Fe2SiAl2+Fe2Si2Al5)and one binary Fe-Al phase(FeAl3).The phases in the coating became Fe2SiAl2+Fe2Si2Al5and FeAl3,the binary Fe-Al phase near the interface became Fe2Al5 and the Si-rich layers were decreased with the increase of heating temperature.When the heat treatment was 1 050℃for 5min,the Si-rich layer disappeared,the coating consisted of FeAl and Fe3 Al,and the Kirkendall voids were formed.When the heating temperature was increased through 870,900,and 930℃,the coating hardness was reduced and cracks were formed in the coating after hot stamping.The formability of the coating with temperature change was confirmed by a hot stamping test.When heated at 1 050 ℃,the coating was formable but continuous Kirkendall voids were observed.     

Effect of the Intercritical Annealing Temperature on the Mechanical Properties of 10 Pct Mn Multi-phase Steel

Intercritically annealed 10 pct Mn steel has been shown to exhibit an excellent combination of strength and ductility due to the plasticity-enhancing mechanisms of mechanical twinning and strain-induced martensite transformation occurring in sequence. This mechanical behavior is only achieved for a multi-phase microstructure obtained after annealing within a specific intercritical temperature range. A model for the selection of the optimal intercritical annealing temperature was developed to achieve a high strength-ductility balance for 10 pct Mn multi-phase steel. The model considers the room temperature stacking fault energy and the thermodynamic stability of the retained austenite.     

Effect of Submerged Arc Softening Welding Flux Component on Temperature

Based on simplex algorithm of optimal design, the multicomponent mixture regression model was used to investigate physical properties of submerged arc welding flux. The effect of complex interaction of seven components in agglomerated flux on softening temperature was analyzed. The results indicate that the interaction of MgO-TiO2-CaCOa-AI20a increases the softening temperature of flux, but the additions of CaF2 and ZrO2 can decrease the softening temperature.     

Effect of Yttrium Addition on Microstructures and Room Temperature Tensile Properties of Ti-47Al Alloy

The microstructures and room temperature tensile properties of a series of Ti-47Al-xY （x = 0%, 0.1%, 0.3%, 0.5%, 0.7% and 1.0%（atom fraction）） were investigated systemically. Results show that both the grain size and lamellar spacing decrease remarkably with the increase of Y content. When the content of Y is greater than 0.1%, most of the Y elements accumulate along the grain boundaries and some fine particles are uniformly dispersed within the grains in the form of YAl2 compound because of the low solubility and segregation of Y in TiAl alloys. Grain-boundary seg- regation of Y element is more prominent with the increase of Y addition. Good tensile properties are obtained when Y addition ranges from 0.3 % to 0.5 %. The refinement of grain and lamellar structures and dispersion of YAl2 within the grains contribute to the improvement of tensile properties. On the other hand, for high Y-added alloys （over 0.5% Y）, tensile properties are obviously deteriorated due to brittle cleavage fracture of the coarse YAl2 network.     

Effect of Submerged Arc Welding Flux Component on Softening Temperature

The study on physical property of flux is veryi mportant,and is correlated to developing advancedsubmerged arc welding(SAW)flux and i mprovingwelding properties.Though some works about fluxproperties,such as viscosity and capillarity,havebeen reported[1,2],the study on softening tempera-ture,one of the flux high temperature propertiesconcerning the melting range,has not been reportedyet.Softening temperature(Ts)has an i mportanteffect on the shape and appearance of the weld andslag detachabil…     

Effect of Temperature on Coal Flotation Performance—A Review

Though substantial coal-washing activities are carried out in a tropical climate, in the 70-yr history of coal flotation, the effect of diurnal and seasonal variations in temperature as an operational variable has received only limited attention. This review examines the current knowledge on the effect of temperature on coal flotation performance and finds that coals with strong natural hydrophobicity do not seem to be affected by a variation in pulp temperature. Difficult-to-float coals, however, appear to float well within a temperature range of 20–35°C with considerable improvement in all flotation indices, concentrate yield and ash, recovery of combustibles, flotation rate, and tailing ash as compared to their values at higher or lower temperature.     

Effect of Cerium on Microstructures and High Temperature Oxidation Resistance of An Nb-Si System In-Situ Composite

Nb-16Si-24Ti-6Cr-6A1-2Hf-xCe （x =0, 0.05, 0.1,02.5, 0.5, 1 （%, atom fraction）） in situ composites were prepared by arc melting The microstmcture and the effect of rare earth element cerium on 1250℃ oxidation resistance of the composites were investigated with scanning electron microscopy （SEM） and X-ray energy disperse spectrum （EDS）, as well as X-ray diffraction （XRD）. The experimental results showed that the high temperature oxidation resistance of the alloy was improved by adding a proper amount of cerium （Ce）. The effect of Ce was considered as the concurrent of the following three factors： first, the oxide of Ce formed in the interface reduced the internal oxidation rate; second, the lath shaped oxide containing Ce increased the cracking resistance and reduced the expansion of the oxide scale; and third, the decrease of the sificide volume fraction on account of Ce addition reduces the power of the sample resisting oxygen penetration.     

Effect of Tempering Temperature on Strength and Toughness of Novel Carbide-Free Bainite/Martensite Duplex Phase Steel

Ｔｈｅｍｉｃｒｏｓｔｒｕｃｔｕｒｅｏｆｓｏｍｅｈｉｇｈｓｔｒｅｎｇｔｈｌｏｗａｌｌｏｙｓｔｅｅｌｓａｎｄｕｌｔｒａｈｉｇｈｓｔｒｅｎｇｔｈｌｏｗａｌｌｏｙｓｔｅｅｌｓｉｎｃｏｍｍｅｒｃｉａｌｕｓｅｉｓｕｓｕａｌｌｙｔｅｍｐｅｒｅｄｍａｒｔｅｎｓｉｔｅ .Ｈｏｗｅｖｅｒ ,ｓｌａｃｋ ｑｕｅｎｃｈｅｄｍｉｘｅｄｍｉｃｒｏｓｔｒｕｃｔｕｒｅｃｏｍｐｒｉｓｉｎｇｍａｒｔｅｎｓｉｔｅａｎｄｂａｉｎｉｔｅｉｓｇｅｎｅｒａｌｌｙｅｎ ｃｏｕｎｔｅｒｅｄｉｎｃｏｍｍｅｒｃｉａｌｐｒａｃｔｉｃｅｗｈｅｎｔｈｅｓｅｌｏ…     

Effect of Rare Earth Elements on Powder Boro-Carbo-Nitriding at Low Temperature

Ｂｏｒｉｄｉｎｇｃａｎｓｉｇｎｉｆｉｃａｎｔｌｙｉｍｐｒｏｖｅｓｕｒｆａｃｅｐｒｏｐｅｒｔｉｅｓｏｆｓｔｅｅｌｓ,ａｎｄｔｈｕｓｉｓａｐｒｏｓｐｅｒｏｕｓｓｕｒｆａｃｅｓｔｒｅｎｇｔｈｅｎｉｎｇｐｒｏｃｅｓｓｗｈｉｃｈｈａｓａｌ ｒｅａｄｙｂｅｅｎｕｓｅｄｉｎｔｒｅａｔｉｎｇｓｏｍｅｄｉｅｓａｎｄｃｕｔ ｔｉｎｇｔｏｏｌｓ[1 ] .Ｈｏｗｅｖｅｒ,ｔｈｅｒｅｅｘｉｓｔｓｏｍｅｐｒｏｂ ｌｅｍｓｉｎｂｏｒｉｄｉｎｇ .Ｆｉｒｓｔｌｙ ,ｂｏｒｉｄｉｎｇｉｓｇｅｎｅｒａｌｌｙｐｅｒｆｏｒｍｅｄａｔｔｅｍｐｅｒａ…     

Effect of Yttrium on Microstructures and Properties at Elevated Temperature of Mg-0.8Zr-0.35Zn Alloys

Asthelighteststructuralmetalmaterial ,themostobviousadvantagesofmagnesiumalloyaretheirhighspecificstrengthandspecificstiffness ,superdampingcapacityandmachinability ,excellentelectromagneticshieldingandnon toxicity .Theincreasingattentionhasbeenpaidonthepracticalapplicationofmagne siumalloysastheenergysavingandenvironmentpro tectionarebecomingtheworldfocus .However ,somedisadvantagessuchasignitableandcombustibledur ingmeltingandcastingandtheirrelativelypoorprop ertiesatelevatedtemperaturelimit…     

Effect of the Rare Earths on the High Temperature Properties of Deformed Leaded-Brasses

The effect of the rare earths on the high temperature properties of deformed leaded-brasses has been stu-died with the high temperature tensile test.The results show that the rare earth additives can increase elongationof alloys at high temperature,but they had little effect on the maximum flow stress.With the help of SEM.X-ray diffraction instrument,quantitative metallography analysis instrument,etc.,the effect of the rare earthelements on the mierostrueture of alloys has also been examined.     

Effect of Yttrium on High Temperature Oxidation Resistance of a Directionally Solidified Superalloy

The effect of rare earth element yttrium on the high temperature oxidation resistance of a directionally solidified Ni-base superalloy was studied with scanning electron microscopy (SEM), energy dispersive spectrum (EDS) and X-ray diffraction(XRD) techniques. The results show that the oxidation resistance of the alloy is substantially improved by adding proper amount of yttrium.     

Effect of Thickness and Annealing Temperature on Magnetic Properties of Ultrathin γ-Fe2O3 Films Grown on Silicon Substrate

The effect of thickness and annealing temperature on magnetic properties of ultrathin γ-Fe₂O₃ films with MgO buffer layer grown on silicon substrate is investigated. The saturation magnetization and coercive force of samples at room temperature increase with increasing of annealing temperature, and decrease as annealing temperature is above 873 K (600 °C). The saturation magnetization of samples decreases with increasing of the thickness of γ-Fe₂O₃ at room temperature. The samples with 3 to 4 nm thick γ-Fe₂O₃ annealed at 873 K (600 °C) show saturation magnetization of about 400 emu/cm³, which is close to the bulk value of ~390 emu/cm³ within the error range.     

Effect of Bonding Temperature on Microstructure and Mechanical Properties of WC–Co/Steel Diffusion Brazed Joint

In this work, the diffusion brazing of AISI 4145 steel to WC–Co cemented carbide using RBCuZn-D interlayer with bonding temperature values of 930, 960, 990 and 1020 °C was studied. The microstructure of the joint zone was evaluated by scanning electron microscope (SEM) and X-ray diffraction (XRD). Vickers microhardness and shear strength tests were performed to investigate mechanical behaviors of the brazed joints. The XRD and SEM results indicated that with increase of bonding temperature, the elements readily diffused along the interface and formed various compounds such as γ, α and β and Co₃W₃C. The results also showed that with the increase of bonding temperature from 930 to 960 °C, a sound metallurgical bond was produced, however in higher bonding temperatures (990 and 1020 °C) a decrease in mechanical properties of the joints was observed which could be due to the excessive zinc evaporation, interface heterogeneity and voids formation. The maximum shear strength of 425 MPa was obtained for the bond made at 960 °C.     

Effect of Microstructure and Mechanical Properties of Al–Mg Alloy Processed by ECAP at Room Temperature and Cryo Temperature

This research primarily focuses on improving the strength of Al 5083 alloy by both the ECAP and Cryo ECAP methodology. Equal Channel Angular Pressing (ECAP) is one of the best technologies that enable the direct transformation of conventional macro grained metals into sub-micron, ultra-fine and nano grained materials. Fine grain size increases the strength and the fracture toughness of the material and provides the potential for super plastic deformation at moderate temperatures and at high strain rates. The microstructure evolution in Al 5083, subjected to Room Temperature ECAP and Cryo ECAP were analysed. ECAP was carried out using an optimized die with Channel angle ‘?’ = 90°and corner angle ‘Ψ’ = 20° through processing route A and C up to four passes. The results were thoroughly studied using TEM, SEM, and optical microscopic images. Initially the annealed sample had the grain size of 80 µm with the equi-axed grains. In Room Temperature, the hardness values and the mechanical strength were found to be increased from 88 to 410 HV and 306 to 453 MPa after four passes in route A and in route C the strength increased from 390 to 416 MPa after four ECAP passes. Moreover, in Cryo Condition, the sample was processed up to four ECAP passes at route A and route C. The hardness of 153 HV was obtained after four passes in route C and 164 HV obtained after four passes on route A. Additionally, fracture behaviour using SEM, grain size using TEM and crystallite size by X-ray diffraction studies were analyzed. It was observed that the Cryo ECAP showed marginal improvements in mechanical properties relative to the RT ECAP in case of Al 5083.     

Thermodynamical Evaluation on Magnetocaloric Effect of Magnetic Refrigerating Materials Near Room Temperature

The relationship between isothermal magnetic entropy change △S and adiabatic temperature change △Tad was deduced according to the principles of thermodynamics. The MCE and the engineering application were discussed for Gd and several new kinds of magnetic refrigerating materials near room temperature, Gd5Si2Ge2, MnFeP0.45As0.55 and LaFe11.2Co0.7Si1.1. Isothermal entropy change is proportional to adiabatic temperature change with a factor of T/C (T is temperature, C is heat capacity). When the comparison of magnetacoloric effect is made for two different materials, we should consider isothermal entropy change as well as adiabatic temperature change.     

Effect of δ Phase on Mechanical Properties of GH4169 Alloy at Room Temperature

Tensile tests of GH4169 alloy were performed at room temperature. Different fractions, distributions and shapes of δ phase was prepared by aging treated at 880 °C, 930 °C and 980 °C for 5 h or 10 h. The effect of δ phase on the mechanical properties of GH4169 alloy was investigated. The results show that 0.2% yield strength and ultimate tensile strength of GH4169 alloy increase by 61 MPa and 78 MPa respectively when the fraction of δ phase increases from 2.20% to 5.21%. Then, the ultimate tensile strength remains at 1 012 MPa even when the fraction of δ phase reaches 7.56%. The fraction effect of δ phase on the strength improvement of GH4169 alloy is more significant than morphology, and the critical fraction value is 5.21%. In addition, the elongation decreases by 14.1% when the fraction of δ phase increases from 2.20% to 7.56%. Excessive needle or short rod shaped δ phase is responsible for the reduction of elongation.     

Effects of Strain Rate and Test Temperature on Torsional Deformation Behavior of API X70 and X80 Linepipe Steels

This study aimed at investigating effects of strain rate and test temperature on deformation and fracture behavior of three API X70 and X80 linepipe steels fabricated by varying alloying elements and hot-rolling conditions. Quasi-static and dynamic torsional tests were conducted on these steels having different grain sizes and volume fractions of acicular ferrite and polygonal ferrite, using a torsional Kolsky bar, and then the test data were compared via microstructures, tensile properties, and adiabatic shear band formation. The dynamic torsional test results indicated that the steels rolled in the single-phase region had the higher maximum shear stress than the steel rolled in the two-phase region, because their microstructures were composed mainly of acicular ferrites. Particularly in the API X80 steel rolled in the single-phase region, increased dynamic torsional properties could be explained by the decrease in the overall effective grain size due to the presence of acicular ferrite having smaller effective grain size. The possibility of the adiabatic shear band formation at low temperatures was also analyzed by the energy required for void initiation and difference in effective grain size.