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1.
稀土提高40Cr钢氮化层抗冲蚀磨损性能的研究   总被引:2,自引:0,他引:2  
程先华  谢超英 《稀土》2000,21(6):22-25
本文研究了在气体氮化渗剂中加入微量稀土元素对40Cr钢氮化层组织、韧性及抗冲蚀磨损性能的影响。试验结果表明稀土在氮化时被渗入到钢的表层起微合金化作用,改善了渗层组织。稀土氮化层的韧性和抗冲蚀磨损性能,较普通氮化层有明显提高。扫描电子显微镜对冲蚀磨损试样表面形貌观察发现,氮化层的磨损特征为塑性变形形成的犁沟剥落,并伴随着萌生横向裂纹,有大块磨屑剥落;而稀土氮化层则为塑性变形形成的犁沟剥落。  相似文献   

2.
加入适量稀土能提高ZG60CrMnSiMo 钢的冲击疲劳抗力,过量反而导致性能恶化。  相似文献   

3.
Magnesiumalloysarewidelyusedinweaponin dustry,spacenavigationandhavegoodpotentialof applicationanddevelopmentindailycommunication facilitiesduetotheirpropertiesoflightweightandhighstrength[1].Appliedasstructuralmaterials,mag nesiumalloysmayeasilycrackduet…  相似文献   

4.
Rollerforcoldrollingisakeyforgingpart,whichexperiencescontactstress ,alter natingstressandfrictionalstressduringrolling .Therefore ,higherstrength ,surfacehardness,wearresistanceandenoughtough nessshouldbeconsideredformanufacturingthiscoldroller[1] .Sincethe…  相似文献   

5.
稀土元素的特殊性质及其应用   总被引:5,自引:0,他引:5  
本文从稀土元素微观结构角度,揭示了稀土元素的某些特殊性质,并指出这种特性与应用机理有必然的联系。从而启迪稀土使用者,掌握和了解稀土的基本特性,才能自由地驾驭稀土的应用。  相似文献   

6.
在奥氏体不锈钢焊条中,通过在焊条药皮中加入稀土元素。探讨了其对焊条熔敷金属组织和性能的影响。对加稀土前后两种焊条进行了熔敷金属常规拉伸和冲击试验。宏观金相组织分析和冲击断口扫描电镜分析。并对熔敷金属薄片进行了透射电镜分析。结果表明:在奥氏体不锈钢焊条药皮中加入稀土元素。可以细化结晶组织,改变晶界上碳化物的析出形态和分布,并使碳化物的析出数量和颗粒尺寸明显减小,从而净化了奥氏体晶界,提高了其焊条熔敷金属的机械性能。  相似文献   

7.
The influence of rare earth (RE) elements on the solidification process and eutectic transformation and mechanical properties of the high-V type cast, high-speed steel roll was studied. Test materials with different RE additions were prepared on a horizontal centrifugal casting machine. The solidification process, eutectic structure transformation, carbide morphology, and the elements present, were all investigated by means of differential scanning calorimetry (DSC) and scanning electron microscopy energy dispersive spectrometry (SEM-EDS). The energy produced by crack initiation and crack extension was analyzed using a digital impact test machine. It was found that rare earth elements increased the tensile strength of the steel by inducing crystallization of earlier eutectic γ-Fe during the solidification process, which in turn increased the solidification temperature and thinned the dendritic grains. Rare earth elements with large atomic radius changed the lattice parameters of the MC carbide by forming rare earth carbides. This had the effect of dispersing longpole M C carbides to provide carbide grains, thereby, reducing the formation of the gross carbide and making more V available, to increase the secondary hardening process and improve the hardness level. The presence of rare earth elements in the steel raised the impact toughness by changing the mechanism of MC carbide formation, thereby increasing the crack initiation energy.  相似文献   

8.
Teapolysacchridecomplex ,oneofthebasicmacromoleculesintea ,hasmanyphar maceuticaleffectsandiseasytodissolveinteainfusion[1] .Zhongetal .[2 ] discoveredthatthereisaREbindingpolysaccharideinleavesofteaplant (CamelliaSinensisLO .Kuntze) .Inthispaper ,thestudyontheco…  相似文献   

9.
利用扫描电镜(SEM)和能谱仪(EDS),研究了不同稀土含量对B级船板钢热轧板断口形貌及对钢中夹杂物形成的影响。研究发现,在B级船板钢中加入稀土后,稀土元素La、Ce能够与钢中的As相互作用形成复合相;稀土在钢中起到变质夹杂物的作用,从而提高了钢的低温冲击韧性;在本实验中,稀土的最佳含量为0.019%。  相似文献   

10.
稀土元素对Fe-Cr-Al系合金抗氧化性的影响   总被引:3,自引:0,他引:3  
彭其春  李光强  朱诚意 《稀土》2003,24(5):13-17
分析了Cr_2O_3膜和Al_O_3膜性质及生长机制,基于国内外学者已提出的机理,讨论了稀土对Fe-Cr-Al系合金氧化膜的生长机制、膜形貌及膜的粘附性的影响。  相似文献   

11.
Rareearths(RE)aresurfaceactiveelements ,theirapplicationsinmetalmaterialscanbesum marizedaspurification ,modificationandall oying[1~ 3 ] .Itisaveryattractivesubjectthattheinter actionofREelementswithlowmeltingpointimpuri tiesintheregionofGBs ,suchasP ,S ,As ,Sbandsoon .ResultsofexperimentsshowthatsegregationinGBsofasmallamountofREinsteelrestrainsharmfulimpuritiessuchasP ,S ,As ,Pb ,Sb ,tosegregateto wardsGBs ,soREelementscancleanseandenhanceGBs ,therebyimprovethehightemperatureducti…  相似文献   

12.
The effect of rare earth elements on eutectic carbide‘s morphology of low chromium semi-steel in as-cast state and after heat treatment was investigated, and accordingly, the thermal fatigue property of this material was studied. The results show that RE can improve the eutectic carbide‘s morphology, inhibit the formation and propagation of thermal fatigue cracks, therefore, promote the thermal fatigue property, which is more noticeable in case of the RE modification in combination with heat treatment. The optimal thermal fatigue property can be obtained when treated with 0.2% RE modification as well as normalization at 950℃ for 3h.  相似文献   

13.
Effect of Rare Earth on Thermal Shock Resistance of Steel 9Cr2Mo   总被引:5,自引:0,他引:5  
Rareearthelementshavebeenaddedintohotrollersteel.REelementscanimprovether malfatigue[1] ,lowfrequencyfatigue[2 ] ,plas ticityandtoughness[3] ,refineausteniticgrainsize[4] andmodifyinclusions[5 ] ofhotrollersteel 6 0CrMnMo .Steel 9Cr2Moisatraditionalcoldrollersteel.When…  相似文献   

14.
15.
Abstract

By using X-ray microanalysis, the mechanism of sorption of rare earth elements (REE) and their localization in cells of Candida utilis were found to depend on the metal ion speciation in solution, the permeability of the cytoplasmic membrane (CPM), and elemental composition of cells. Sorption capacity of the yeast cells increased with the increase in the pH of solution, which is connected with the extent of metal hydrolysis. Cells with native permeability of CPM did not sorb either scandium at pH values below 4.5 or lanthanum and samarium at pH values below 5.0. Such cells accumulate rare earth elements on surface structures. Only the cells with impaired CPM could sorb REE from the acid solutions. In this case, REE were accumulated inside the cells due to the interaction with phosphorus-containing compounds; the amount of sorbed REE depended on the content of phosphorus in the yeast cells. The yeast cells were shown to have extremely high affinity to scandium which thus can be selectively sorbed from solutions containing other REE, iron, and aluminum.  相似文献   

16.
王进福  韦永德  金为国 《稀土》2002,23(4):39-42
研制了新型的稀土摩阻材料。摩阻材料刹车片中 ,钢纤维通过气 -固表面扩渗稀土处理后 ,表面耐腐蚀性能明显改善 ,抗冲击强度显著提高 ,并且综合性能有所改善。比较了经过渗稀土处理钢纤维与未经渗稀土处理钢纤维制备的摩阻材料刹车片耐腐蚀性能和抗冲击性能 ,初步分析探讨了可能的机理  相似文献   

17.
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   

18.
赤泥矿中的稀土元素测定方法的研究   总被引:1,自引:0,他引:1  
对目前较常用的稀土元素的测定方法进行了综述,分别探讨了各方法的优缺点.并着重研究了采用ICP-AES(电感耦合等离子体发射光谱仪)来测定赤泥矿中的15种稀土元素的方法,进行了一系列实验,结果表明,该方法用来检测稀土元素可行有效、方便快捷、精密度高.  相似文献   

19.
稀土元素对T_(10)钢冲击韧性和断口形貌的影响   总被引:4,自引:0,他引:4  
本文研究了添加稀土元素的T(10)钢冲击性能和断口形貌的关系。试验表明,在T(10)钢中添加稀土元素对硬度没有明显的影响,但能显著改善该钢的冲击韧性。对稀土改善T(10)钢冲击韧性和断口形貌的原因进行了初步讨论。  相似文献   

20.
Role of Rare Earth in Low Sulphur Nb-Ti-Bearing Steel   总被引:2,自引:0,他引:2  
The effect of rare earth on the microstructures, mechanical properties and inclusions in low sulphur Nb-Ti-bearing steel were investigated. It is shown that the transverse yield point, the traverse tensile strength and elongation of testing steels decrease initially and then rise with increasing content of rare earth. The impact energy values of the testing steels exhibit a contrary trend. Proper amount of rare earth in the steels can improve the anisotropy of impact toughness above -20℃ and it does not affect the type of microstructures which are still composed of ferrites and pearlites, but the pearlite amount increases. On one hand, rare earth cleans the molten steel and reduces the amount of inclusions; on the other hand, rare earth makes the inclusions spheroidizd, refined and dispersed, and thus improves the distribution of inclusions.  相似文献   

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