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本文利用X射线定量相分析及金相观察和硬度测试,考察了中碳Fe-Mn-Ni-Cr钢的组织及合金元素的作用。建立了经1100℃淬火后的马氏体体积分数与合金成分的定量关系式; f_M~(1100)=162.643-15.482Mn-7.36Ni-4.286(Cr+Mo+V)并在此基础上给出了亚平衡组织图。结果表明,Mn稳定奥氏体的作用大于Ni的作用。Ni和Cr当量分别以[Ni]=2.104Mn+Ni,[Cr]=Cr+Mo+V表示。计算了M_S点处的马氏体相变驱动力,指出Mn具有强烈降低相变驱动力的作用。 相似文献
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C.C. Zhang C.S. Yang G.F. Ding S. Q. Qian J.S. Wu 《金属学报(英文版)》2005,18(6):707-713
Microstructure and phase transformation behaviors of the film annealed at different temperatures were studied by X-ray diffractometry (XRD), transmission electron microscopy and differential scanning calorimeter (DSC). Also tensile tests were examined. For increasing annealed temperature, multiple phase transformations, transformations via a B19-phase or direct martensite/austenite transformtion are observed. The TiNiPd thin film annealed at 750℃ had relatively uniform martensite/austenite transformtion and shape memory effect. Martensite/austenite transformtion was also found in strain-temperature curves. Subsequent annealing at 450℃ had minor effect on transformation temperatures of Ti-Ni-Pd thin films but resulted in more uniform transformation and improved shape memory effect. 相似文献
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应变速率对低C高Mn TRIP/TWIP钢组织演变和力学行为的影响 总被引:1,自引:0,他引:1
研究了Fe-18Mn低C高Mn TRIP/TWIP钢在应变速率范围为1.67×10-4-103s-1的室温拉伸实验过程中力学性能和组织的变化.在准静态拉伸应变速率范围内(1.67×10-4-1.67×10-1s-1),应变速率对高Mn TRIP/TWIP钢的抗拉强度产生逆效应,随着应变速率的加快,抗拉强度和延伸率都降低;而在动态拉伸应变速率范围内(101-103s-1),应变速率对高Mn TRIP/TWIP钢的延伸率产生逆效应,抗拉强度和延伸率都随着应变速率的加快而增加;在应变速率为103s-1时,高Mn TRIP/TWIP钢抗拉强度可达到957 MPa,延伸率达到55.8%,具有较好的综合力学性能;随着应变速率的提高,马氏体转变量减少,孪生变形向多个方向发展.采用SEM,TEM和XRD等方法对变形前后的组织进行了分析,在所有应变速率范围内的拉伸变形过程中都产生了奥氏体向马氏体转变和形变孪晶,并且在应变速率为103s-1的高速拉伸过程中产生绝热温升效应,使得基体软化. 相似文献
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铸造TiAl—W—Si合金的组织转变 总被引:2,自引:0,他引:2
研究了热处理及合金元素W对TiAl合金显微组织的影响,探讨了该合金随温度变化发生的相转变规律。1300℃热处理时部分溶解的层片组织在随后冷却过程中由α固溶体形成细的层片晶团,而未溶解部分则发生连续和不连续长大而粗化。随着W含量的增加,不但有序β相增加,而且以多种形态出现,同时层片组织不稳定,易产生双态组织。从合金加热到熔化,再冷却至800℃的差热分析,结合显微组织的研究,得出该合金的相转变规律为: 相似文献
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混合稀土对AZ91D镁合金组织和力学性能的影响 总被引:18,自引:2,他引:18
研究了添加混合稀土(0.02%-1.2%,质量分数)对AZ91D镁合金晶粒大小、枝晶大小、共晶组织、凝固曲线特征参数和力学性能的影响.结果表明,混合稀土与合金中Al8(Fe,Mn)5或ε-AlMn相反应生成Al—RE—Mn三元相,减少了合金熔体中异质形核核心的数目,从而导致晶粒和枝晶的粗化;混合稀土还与Al反应生成Al11RE3相,消耗了部分Al,使得共晶组织减少.在砂型凝固条件下,随着混合稀土添加量的增加,AZ91D镁合金的初晶形核最低温度从595.2升到597.3℃;共晶最低温度先从427.7升到431.2℃,再降到428.7℃;共晶生长温度先从428.7升到431.8℃,再降到429.9℃;共晶再辉温差则存在波动.添加混合稀土降低了AZ91D镁合金的室温强度,但提高了合金的高温强度和延伸率. 相似文献
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SUN Enxi Dalian Railway College Dalian ChinaYANG Dazhi Dalian University of Technology Dalian ChinaXU Zuyao 《金属学报(英文版)》1991,4(1):8-12
The pulsed magnetic field induced martensitic transformation with isothermal and athermal kinetics in Fe-2Ni-4Mn(wt-%)alloy has been studied by means of magnetization measurements,optical microscopy and thermodymical analyses.It is shown that there exits a critical magnetic intensity for induing martensitic transformation at a given temperature above Ms.The critical magnetic field increases linearly with increasing ΔT= T-M_S.The magnetic field strongly promotes the athermal martensitic transforamtion and restrains the isothermal one.The entropy change ΔS for athermal transformation at Ms is 4.13 J/mol· K.The effect of magnetic field on martensitic transformation in Fe-21Ni-4Mn alloy is main- ly due to Zeeman effect.Lath,plate and butterfly martensities were observed under magnetic field. 相似文献
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磁场强度对Fe-0.76%C合金先共析铁素体显微组织的影响 总被引:1,自引:0,他引:1
借助于光学显微镜研究了磁场强度对Fe-0.76%C合金冷却转变过程的先共析铁素体显微组织的影响.结果表明:随着磁场强度的增强,该合金的先共析铁素体析出量和共析点的含碳量均明显增加.原因可归结为,强磁场使Fe-C合金的共析点向高温及高含碳量区域移动,使奥氏体向铁素体转变的初始温度升高.强磁场使先共析铁素体沿磁场方向伸长,而且随着磁场强度的增加,先共析铁素体的伸长方向与磁场方向之间夹角的平均值逐渐减小.上述现象可解释为:外加磁场使先共析铁素体晶核成为磁偶极子,并使其周围奥氏体原子作为磁偶极子更易于沿磁场方向向铁素体晶核扩散. 相似文献
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EFFECT OF MELT SUPERHEATING ON MICROSTRUCTURE AND MECHANICAL PROPERTIES OF A357 ALLOY 总被引:2,自引:0,他引:2
Li Peiyong Jia Jun Guo Jingjie Li Peijie Shao Gaoliang School of Materials Science Engineering Harbin Institute of Technology Harbin Beijing Research Institute of Aeronautical Materials Beijing 《中国有色金属学会会刊》1997,(3)
EFFECTOFMELTSUPERHEATINGONMICROSTRUCTUREANDMECHANICALPROPERTIESOFA357ALLOY①LiPeiyong1,2,JiaJun,GuoJingjie,LiPeijie,ShaoGaolia... 相似文献
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ZHANG Guilin XU Feng LIU Wenhong YU Fanghua Shanghai Institute of Nuclear Research Academia Sinica Shanghai ChinaWANG Jingcheng SHAO Zichang Shanghai Iron Steel Research Institute Shanghai China 《金属学报(英文版)》1992,5(5):345-348
Effect of γ-irradiation on the shape memory alloy CuZnAl has been studied by the techniquesof TEM,positron annihilation etc..The martensitic transformation temperature of the alloyincreases obviously ofter γ-irradiation at a dose of 2×10~7 Gy but not for a dose of 1×10~7 Gy.The shape memory effect in both irradiated alloys remains unaffected. 相似文献
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YU Guifu Beijing Institute of Aeronautical Materials Beijing ChinaHE Junfang Institute of Metal Research Academia Sinica Shenyang ChinaLI Qingchun Harbin Institute of Technology Harbin China 《金属学报(英文版)》1992,5(4):256-260
The microstructure and properties of the rapidly solidified Al-Li-Mg-Zr alloy,in relation tothe particle size of supersonic atomizing powder,have been investigated.The finer the size andthe structure of powder,the higher the strength of the alloy.While the overfine powder mayworsen plasticity of the alloy.The proper powder seems to be sized 40—100um. 相似文献
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采用透射电镜、扫描电镜、能谱分析、Tafel曲线、计时-电位法(E-T曲线)和析氢测量等现代分析测试方法研究了不同轧制温度的Al-Mg-Sn-Bi-Ga-In铝合金阳极的显微组织变化及其在80℃,添加Na2SnO3缓蚀剂的5 mol/L NaOH电解液中的电化学性能和耐腐蚀性能。结果表明:当控制道次变形量为40%时,随着轧制温度的升高,铝合金阳极的显微组织经历了从位错胞状组织、亚晶组织到动态再结晶组织的转变过程。在轧制温度为420℃进行轧制时,合金中Sn和In等活性元素分布均匀,偏析相减少,铝合金阳极电极电位负移至-1.48V(vs•Hg/HgO)左右,析氢腐蚀速率也降为0.1716 mL/(cm2•min),说明该轧制工艺条件下,铝合金阳极电化学综合性能较好。 相似文献
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M. Militzer The Centre for Metallurgical Process Engineering University of British Columbia Vancouver BC Canada VT Z 《金属学报(英文版)》2000,13(2):574-580
1.IntroductionMicrostructureprocessmodelsareincreasinglyonhotstriprollingofste.l[1--7].Thesemodelsfrequentlyincorporateagreatdealofempiricismwithcomparativelytightprocessrangesofapplicability.Morefundamentallybasedprocessmodelsarerequiredtodeveloppredictivetoolstooptimizetheproductionforawiderangeofmilldesignsandprocessingconditions.Theprocessofhotstriprollingoflow--carbonsteelscanbesubdividedintothreeprin-cipalstages:(i)reheating,(n)rollingand(iii)cooling(watercoolingontherun--outtableandsubs… 相似文献
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轧制工艺对7050铝合金显微组织和力学性能的影响 总被引:5,自引:0,他引:5
研究了轧制变形量和轧制温度对7050铝合金显微组织和力学性能的影响.当轧制变形量为30%时,轧制样品中大部分晶粒还基本保持铸态的枝晶形状;当变形量在70%以上时,铸态组织完全消失,并出现再结晶晶粒和亚晶组织.能谱结果表明,轧制样品中粗大的第二相为Al7Cu2Fe和Al2CuMg,AI7Cu2Fe相不溶于基体且呈链状分布,而Al2CuMg相部分溶于基体且呈球状分布.变形量为70%和90%样品的再结晶晶粒分数分别为1.25%和12.4%.变形量为70%样品的强度和硬度最高.当轧制温度为300℃时.时效后的样品中出现较多的再结晶晶粒;轧制温度升至430℃时,材料流变性变好.并且在轧制过程中更容易发生动态回复,使储存的变形能减少.再结晶晶粒明显减少,强度和硬度也达到最高. 相似文献