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1.
Effect of Sulfate Reduced Bacterium on Corrosion Behavior of 10CrMoAl Steel   总被引:1,自引:0,他引:1  
 The effects of sulfate reduced bacterium (SRB) on the corrosion behavior of 10CrMoAl steel in seawater were studied by chemical immersion, potentiodynamic polarization, electrochemical impedance spectroscopy measurement, and scanning electron microscope techniques. The results show that the content of element sulfur in the corrosion product of 10CrMoAl steel in seawater with SRB is up to 923%, which is higher than that of the same in sterile seawater. X ray diffraction demonstrates that the main corrosion product is FeS. SRB increases the corrosion rate by anodic depolarization of the metabolized sulfide product. SEM observation indicates that the corrosion product is not distributed continuously; in addition, bacilliform sulfate reduced bacterium accumulates on the local surface of 10CrMoAl steel. Hence, SRB enhances sensitivity to the localized corrosion of 10CrMoAl steel in seawater.  相似文献   

2.
Thermal–mechanical analysis of solidification is important to understand crack formation, shape problems, and other aspects of casting processes. This work investigates the effect of grade on thermal–mechanical behavior during initial solidification of steels during continuous casting of a wide strand. The employed finite element model includes non-linear temperature-, phase-, and carbon content-dependent elastic–viscoplastic constitutive equations. The model is verified using an analytical solution, and a mesh convergence study is performed. Four steel grades are simulated for 30 seconds of casting without friction: ultra-low-carbon, low-carbon, peritectic, and high-carbon steel. All grades show the same general behavior. Initially, rapid cooling causes tensile stress and inelastic strain near the surface of the shell, with slight complementary compression beneath the surface, especially with lower carbon content. As the cooling rate decreases with time, the surface quickly reverses into compression, with a tensile region developing toward the solidification front. Higher stress and inelastic strain are generated in the high-carbon steel, because it contains more high-strength austenite. Stress in the δ-ferrite phase near the solidification front is always very small, owing to the low strength of this phase. This modeling methodology is a step toward designing better mold taper profiles for continuous casting of different steels.  相似文献   

3.
Thestudies[1,2 ] havestatedthatretainedausteniteinadual phasesteelistransformedtomartensiteundertensilestrain .Suchstrain inducedtransformationofretainedaustenitecanenhanceductilityofsteelwhentheretainedausteniteisratherstableagainststraining[3 ] .Basedonthi…  相似文献   

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6.
Effect of Ca^2+ and Mg^2+ on CO2 Corrosion Behavior of Tube Steel   总被引:1,自引:0,他引:1  
Corrosionfailurecasesobservedinoil fieldaremainlycausedbylocalcorrosion ,whicharealwaysfoundinthedefectareasofcorrosionproductlayer .Thecompositionandmicrostructureofcorrosionprod uctlayeraffectthecorrosionrateandcorrosionmor phologystrongly[1- 3] .Ca2 a…  相似文献   

7.
EfectofRareEarthsonTensileBehaviorofHotRolerStel60CrMnMoandEstimationofRol′sFatigueLifeYangQingxiang(杨庆祥),ZhuGuangrong(朱广荣),...  相似文献   

8.
EfectofRareEarthsonTemperedMartensiteEmbritlementofStelGaoGuozhong(高国忠),HeWeiyong(贺维勇),GaoJu(高炬),ChenJizhi(陈继志)(InstituteofM...  相似文献   

9.
Effect of Rare Earths on Properties of BNbRE Rail Steel   总被引:1,自引:0,他引:1  
The development and properties of BNbRE rail steel and the effect of RE on rail steel were studied. The results show that the properties of rail steel (δb ≥980 MPa, δ5≥ 8 % ) can be improved by adding RE and niobium and adjusting the content of C, Si and Mn in steel. At the same time, the abrasion resistance, contact fatigue and fatigue property of BNbRE rail steel are excellent. It also shows that RE in rail steel has the functions of purifying steel, modifying inclusion and micro-alloy action effect. The improved steel-making process enhances the quality of molten steel. Although the content of RE is low, excellent properties of BNbRE rail steel are achieved.  相似文献   

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11.
Effect of Cerium on Gas Evolution Behavior of Pb-Ca-Sn Alloy   总被引:1,自引:0,他引:1  
Hydrogen and oxygen evolution reactions areharmful to the valve regulate lead acid battery duringcharging and discharging processes.Oxygen evolutionreaction occurs at the positive electrode in the leadacid battery and transfers from baffle to the negativeelectrode,reducing to water finally.Hydrogen evolu-tion reaction takes place occasionally on the negativeelectrode inthe lead acid battery.In general,the rateof hydrogen oxidation reaction on the negative elec-trode is lower or less hydrogenis…  相似文献   

12.
 The addition of Cu 10Sn alloy for developing the high strength 465 maraging stainless steel from elemental powders was studied. The sintering parameters investigated include the sintering temperature, the sintering time, and the mass percent of Cu 10Sn. For vacuum sintering, effective sintering occurs at temperature between 1 250 ℃ and 1 300 ℃. The maximum sintered density was achieved at 1 300 ℃ for 60 min with 3% (in mass percent) Cu 10Sn alloy. More than 3% (in mass percent) Cu 10Sn content and temperature above 1 300 ℃ caused slumping of the samples. A maximum density of 74 g/cm3 was achieved with 3% (in mass percent) Cu 10Sn content at a sintering temperature of 1 300 ℃ for 60 min. A maximum ultimate tensile strength (UTS) of 517 MPa was achieved with 3% (in mass percent) Cu 10Sn content. With content higher than 2% (in mass percent) Cu 10Sn, a maximum increase in the density was observed. The fracture morphologies of the sintered samples are also reported.  相似文献   

13.
EffectofCeriumonStructureandPropertiesofGranularBainiticSteel¥WangFuming(王福明),LiJinhui(李景慧),HanQiyong(韩其勇)(DepartmentofPhysic...  相似文献   

14.
A technique of treating steel with rare earth fluoride complex additives(REFCA),effects andinflunce factors have been studied.REFCA play a role on controlling inclusion morphology,purifying themolten steel and improving properties of steel.The optimum composition of REFCA is REF_3 42%;CaO33%;SiCa 25%,and the amount of REF_3 is 0.5 wt%~0.6 wt% of steel.  相似文献   

15.
The polycrystalline samples of La2/3Ca1/3MnO3 were prepared by a conventional solid state reaction method. The magnetizations (ZFC, FC and initial magnetization) of the polycrystalline La2/3Ca1/3MnO3 were measured with superconducting quantum interference device magnetometer. The scaling theory was employed to study the changes of critical behavior arising from the applied external field. The critical parameter β decreases with increasing the external magnetic field results in an increase in the magnitude of ferromagnetic ordering.  相似文献   

16.
RecentlythebeneficialactionsofREonironandsteelshavebeenreportedaroundtheworld.REcannotonlydeoxidizeanddesulphurizethemeltandf...  相似文献   

17.
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.  相似文献   

18.
The processing conditions of the texture formation and deep drawability of a Ti-IF steel strip hot-rolled in ferritic region and subsequently annealed were investigated. The r-value increases with the decrease of reheating temperature, and finish rolling temperature and the increase of reductions in ferritic region. For lubricated ferritic rolling and annealing, the r-value is raised up to 1.75, and elongation rate is over 50% at the finish rolling temperature of 650 ℃, which is suitable for DDQ grade products. However, the r-value is below 1.0 in the case of unlubricated rolling. The X-ray diffraction was used to analyze the textural characteristic of samples. For samples subjected to lubricated rolling and annealing, the strong { 111 }//ND recrystallization texture is distributed homogeneously along the thickness direction, and the intensity of { 110} recrystallization texture is very low even in surface. However, for unlubricated samples, the {111} texture is distributed inhomogeneously and is weak along the thickness direction, and (110}//ND recrystallization texture is strong, which deteriorates the formability.  相似文献   

19.
Liningplateisoneofthemostimportantwear resistantcomponentsofballmills .Itmustmeetvar iousrequirementsforthemachinesaccordingtoop eratingconditions .Recently ,aseriesofwear resis tantmaterialshasbeendevelopedfordifferentballmillsinChina ,e .g .high carbonmediu…  相似文献   

20.
The effects of RE modification on structure and the properties of a new cast hot-work die (CHD) steel were investigated. The grains of the CHD steel are refined by RE modification. With the increase of RE addition, both grain size and inclusion amount are reduced. Appropriate amount of RE results in decrease in inclusion amount and formation of spheroidal inclusions uniformly - distributed in steel, so that the morphology and distribution of inclusions are improved. RE composite modification favors the formation of bainite, austenite and fine lath martensite with dense dislocation. When the residual RE content reaches 0.02 %, no obvious changes in strength and hardness are found, while fracture toughness and threshold of fatigue crack growth are increased. The impact toughness, elongation and reduction of cross sectional area are increased by a factor of two, and thermal fatigue resistance is also improved.  相似文献   

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