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1.
The microstructures and properties of X60 grade pipeline strip steel were researched.With Nb microalloying and TMCP,the X60 grade pipeline strip steel was developed in the Baotou CSP Plant.The mechanical properties meet the demands on machining and using of pipeline manufacture.The X60 strip steels had been used extensively,which had fine and uniform structures,good performance and excellent toughness.  相似文献   

2.
The effects of B and Ce on the removal of inclusions, microstructures, and properties of Cu-Fe-P alloys were studied. Certain impurity elements and the microstructures, mechanical properties, and conductivity of four experimental alloys, Cu-0.22Fe-0.06P, Cu-0.22Fe-0.06P-0.05Ce, Cu-0.22Fe-0.06P-0.02B, and Cu-0.22Fe-0.06P-0.05Ce-0. 02B ( %, mass fraction), were tested and analyzed. Results show that on one hand, B and Ce have a remarkable function of removing S, Pb, and Bi from copper alloys ; on the other hand, the recrystallization temperature of the Cu-Fe-P alloy is considerably increased by adding trace B and Ce, resulting in the combined strengthening effect of precipitation hardening and cold work hardening after cold working and aging, while the negative effect of B and Ce on conductivity is slight. Therefore, a good combination of high strength and conductivity is achieved.  相似文献   

3.
Earlier May, China Electricity Council made forecast to the nationwide power supply and demand for the 2nd quarter of 2007 .  相似文献   

4.
With the X65 pipeline steel as raw material,we researched the influence of Ce on the organization and the low-temperature impact toughness.The result of the experiment was that:Ce had big influence on the organization and mechanics capability of X65 pipeline steel,Ce could thin the solidification to improve the capability of the steel.1# sample that was X65 pipeline steel without RE had dimple and uneven,its dimple and grain size was biggish;1# sample with RE’s dimple was small and uniform.The low-temperature impact and impact energy of 2# sample with RE were both higher.  相似文献   

5.
Titanium having high demand in aircraft industries because of its mechanical properties like high strength to weight ratio, high temperature performance and it’s resistant to corrosion. Therefore, Titanium and its alloys are used in airplane and engine applications. One of the major usages of alloy in the aircraft industries are Titanium alloy. By using Powder Metallurgy, the powder materials are compacted and sintered in the furnace to achieve high densities for the further process of the samples. In this paper reviews the various research investigations of Titanium and its alloy (Ti–% Al–% V–% X alloy), to optimize the microstructure and mechanical properties by various sintering methods like Conventional, Spark plasma and Microwave sintering techniques. From this the major advantages in the Spark plasma sintering tend to reduce the sintering time with high temperatures, achieving higher densities and improved microstructures tends to improve the mechanical properties of the material.  相似文献   

6.
Conclusions We examined the behavior of two materials during high-temperature oxidation: the singlephase -sialon and the material based on -sialon containing up to 8% residual -Si3N4 and the glass phase produced by reaction sintering of the charge based on -modification of silicon nitride. The results show that the maximum oxidation resistance in the temperature range 800–1300°C is exhibited by the single-phase -sialon Si5.5Al0.5O0.5N7.5. The oxidation resistance decreases in the presence of the residual -Si3N4 and the glass phase in the material. The oxidation kinetics are also determined by the structure and composition of the oxide film. The kinetic curves are governed by a parabolic law which indicates that oxidation of the sialons is limited by the diffusion processes. No marked changes were detected in the lattice spacing of the sialon after oxidation.Translated from Poroshkovaya Metallurgiya, No. 6(306), pp. 69–73, June, 1988.  相似文献   

7.
SynthesisandCrystalStructureofHeteronuclearComplexofCopperandYtriumwithGlycineWangRuiyao(王瑞瑶),GaoFeng(高峰),JinTianzhu(金天柱)(...  相似文献   

8.
9.
EffectofFluoridesandCeriumDioxideAdditivesonEPandAntiwearPerformanceofGreaseLianYafeng(连亚锋)(GuangzhouMachineToolResearchInsti...  相似文献   

10.
11.
~~Internal Friction and Profile of Property and Structure of PD_3 and PD_3RE Rail Steels  相似文献   

12.
ItiswelknownthatthemechanicalpropertiesofgraycastironcanbeimprovedbyaddingsuitableamountofREandN.Tohighcarbonequivalent(CE)gr...  相似文献   

13.
To quest for the best combination of mechanical properties and exfoliation corrosion resisting property of Al-Mg-Mn base alloys, and to seek after the effect of Sc and Zr on mechanical and exfoliation corrosion properties of Al-Mg-Mn alloys, comparative research technique was used, the mechanical properties of Al-Mg-Mn alloys with and without minor Sc and Zr treated by different annealing were measured, the degrees of exfoliation corrosion for these alloys through accelerated exfoliation corrosion test were evaluated, and polarization curves of these alloys were measured, too. The micro-morphologies of corrosion specimens were observed by SEM and the corrosion product was analyzed using EDS. Optical microscope and TEM were used, the relationship between their microstruc-tures and mechanical properties, exfoliation corrosion resisting property was investigated, and the results show that the addition of minor Sc and Zr can enhance the strength greatly and also improve the combination of strength and plasticity. Moreover, the addition of minor Sc, Zr does not cause appreciable decrease of exfoliation corrosion resisting property, the Al-Mg-Mn-Sc-Zr alloy annealed at 350 ℃ for 1 h has excellent combination of mechanical properties and exfoliation corrosion resisting property, the satisfied combination of mechanical properties nad exfoliation corrosion resisting property can be obtained by means of adding minor Sc and Zr, decreasing the content of Mn, and adopting reasonable annealing practice.  相似文献   

14.
Rareearthelementshavebeenincreasinglyusedinagriculture ,animalhusbandryandfisheryinChinasinceREcanpromotegrowthofcropsandani mals[1,2 ] .However ,studieshaveshownthatoverex posureofREmayhavenegativeortoxiceffectsonor ganisms ,forexample ,inhibitingenzymeactivityandinterferinginmetabolism ,havinghighaffinitytoCa2 bindingsitesanddown regulatingabsorptionandfunc tionofCa2 ,blockingbloodclotting ,inducingpatho histologicallesionsofliver ,aswellasaffectinggo nadalfunction[3~6 ] .Furthermore ,…  相似文献   

15.
The present study compares the fatigue and fracture properties of the high-strength β titanium alloy β-Cez with the conventional α+β titanium alloy Ti-6Al-4V, because of increasing interest in replacing α+β titanium alloys with β titanium alloys for highly stressed airframe and jet engine components. This comparison study includes the Ti-6Al-4V alloy in an α+ β-processed condition (for a typical turbine blade application) and the β-Cez alloy in two distinctly different α+β-processed and β-processed conditions (optimized for a combination of superior strength, ductility, and fracture toughness). The comparison principally showed a much lower yield stress for Ti-6Al-4V (915 MPa) than for both β-Cez conditions (1200 MPa). The Ti-6Al-4V material also showed the significantly lower high-cycle fatigue strength (resistance against crack initiation) of 375 MPa (R=−1) as compared to the β-Cez alloy (∼600 MPa, R=−1). Particularly in the presence of large cracks (>5 mm), the fatigue crack growth resistance and fracture toughness of the Ti-6Al-4V material is superior when compared to both β-Cez conditions. However, for small crack sizes, the conditions of both the alloys under study show equivalent resistance against fatigue crack growth. For the β-Cez material, where microstructures were optimized for high fracture toughness (conventional large crack sizes) by thermomechanical processing, maximum K Ic-values of 68 MPa√m of the β-processed β-Cez condition (tested in the longitudinal direction) decreased by ∼50 pct in the presence of small cracks (1 mm). A similar decrease in fracture toughness was obtained by loading the β-processed β-Cez condition perpendicular to the flat surfaces of the pancake-shaped β grain structure (tested in the short transverse direction). These results were discussed in terms of the effectiveness of the crack front geometry in hindering crack propagation. Further, the results of this study were considered for alloy selection and optimized microstructures for fatigue and fracture critical applications. Finally, the advantage of the α+β-processed β-Cez condition in highly stressed engineering components is pointed out because of its overall superior combination of fatigue crack initiation and propagation resistance (especially against small fatigue cracks).  相似文献   

16.
TheartificialnucleasesforcleavingDNAhavebecomemoreimportant.Theenzymesystemmimicing theenzymaticsiteisthedicopperenzymehemocyanin thathasattractedmoreinterest[1~5].Somestudiesre portedthatmanynaturalenzymeswiththegoodactivi tiesalwayscontaintwoorthreeint…  相似文献   

17.
StudiesonSolventSystemofCesiumChlorideandLanthanumChlorideandSynthesizationofFourTypesofNewCompoundsLiYahong(李亚红),RanXinquan...  相似文献   

18.
In order to improve the hydrogenation and dehydrogenation performances of the Mg2Ni-type alloys, Mg was partially substituted by La in the alloy, and melt spinning technology was used for the preparation of the Mg20-xLaxNi10 (x=0, 2, 4, 6) hydrogen storage alloys. The structures of the alloys were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM). It was found that no amorphous phase formed in the as-spun La-free alloy, but the as-spun alloys containing La held a major amorphous phase. When La content x≤2, the major phase in the as-cast alloys was Mg2Ni phase, but with further increase of La content, the major phase of the as-cast alloys changed into LaNi5+LaMg3 phase. Thermal stability of the as-spun alloys was studied by differential scanning calorimetry (DSC), showing that spinning rate was a negligible factor on the crystallization temperature of the amor-phous phase. The hydrogen absorption and desorption kinetics of the as-cast and as-spun alloys were measured using an automatically con-trolled Sieverts apparatus, confirming that the hydrogen absorption and desorption capacities and kinetics of the as-cast alloys clearly in-creased with rising La content. For La content x=2, the as-spun alloy displayed optimal hydrogen desorption kinetics at 200 ℃.  相似文献   

19.
Themetalcomplexesofhydrazideshaveattractedconsiderableinterestowingtotheirantifungalandantibacterialactivities[1 ,2 ] .Theycanalsobeusedasanalyticalreagents[3 ]andextractingagentsformetalsalts[4 ] .Manycomplexesofhydrazideshavebeensynthesizedandcharacterized[5]…  相似文献   

20.
OxidationandAntioxidationofNanocrystalinePowdersofNdFeBWenDijiang(闻荻江)(ScholofChemistryandChemicalEnginering,SuzhouUniversi...  相似文献   

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