共查询到19条相似文献,搜索用时 62 毫秒
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2205双相不锈钢的高温变形行为 总被引:4,自引:0,他引:4
利用Gleeble-3800热力模拟试验机在温度为1223-1523 K, 应变速率为0.01-10 s-1的条件下进行了2205双相不锈钢热压缩变形实验, 测定了真应力-真应变曲线, 分析了变形组织. 结果表明: 奥氏体分布在随温度升高而含量增加的铁素体基体上, 升高温度和降低应变速率可促进奥氏体发生动态再结晶. 基于热变形方程计算得到了热变形激活能Q=451 kJ/mol, 表观应力指数n=4.026. 真应力-真应变曲线存在的“类屈服平台”效应与Z参数有关, 随着Z参数的减小而逐渐增强. 基于简化应力函数的ln Z与σp之间的线性关系在临界点(ln Zc=38.18)发生偏移;峰值应力与温度及应变速率的关系可表示为: σp=20.6lnε+1118002/T-266.8(ln Z>38.18); σp=9.1lnε+493874/T-701.9(ln Z≦38.18) 相似文献
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利用Gleeble-3800热模拟试验机对新型Co-Ni基高温合金进行热压缩试验,研究其在变形温度为950~1100℃、应变速率为0.01~10 s-1、真应变为0.693时的热变形行为和微观组织演变。结果表明,合金流动应力随变形温度的升高或应变速率的降低而减小。合金平均晶粒尺寸随变形温度的升高而增加,降低变形温度和提高应变速率可细化动态再结晶晶粒。基于EBSD和TEM分析表明,合金热变形过程中非连续动态再结晶(DDRX)作为主要动态再结晶(DRX)机制,孪晶形核作为辅助形核机制。 相似文献
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Mg-Y及AZ31镁合金高温变形过程中微观织构的演化 总被引:1,自引:0,他引:1
在温度为723 K、应变速度为3×10-3 s-1的条件下,对Mg-Y及AZ31镁合金挤压棒材进行单向压缩变形,利用OM、SEM和EBSD观察、分析Y对挤压棒材动态再结晶和微观织构的影响。结果表明:AZ31镁合金在真应变ε=0.2时发生明显的动态再结晶,在ε=0.5时,动态再结晶晶粒的体积分数高达80%以上;而Mg-Y合金在真应变ε=0.4时,动态再结晶体积分数尚不足10%,Y对镁合金动态再结晶有显著的阻碍作用;AZ31镁合金变形时,几乎所有晶粒的基面趋向于由变形前平行于压缩方向转至垂直于压缩方向,导致基面织构在ε=1.2时发生近90°的转动;Mg-Y合金则只有小部分晶粒发生转动,转动所形成的择优取向在动态再结晶后显著弱化,并导致取向分布更加随机;Y的添加可导致镁合金基面织构在动态再结晶后显著弱化。 相似文献
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采用Gleeble-1500热模拟实验机对AZ91D镁合金在400℃、0.01s^-1的条件下进行不同压缩真应变量(1%、10%、60%、100%)的高温压缩实验,利用光学显微镜、透射电镜观察压缩变形过程中合金的显微组织演变。结果表明:在压缩变形的初始阶段,{101^-2}孪生是主要的变形机制,孪晶的尺寸较大;在随后的变形过程中孪晶发生破碎,尺寸变小;随着变形的进一步进行,孪晶之问相互交叉,在孪晶界及孪晶交叉畸变较大的区域成为再结晶的形核区。 相似文献
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XU Yourong GU Qing WANG Deying Shanghai University of Science Technology Shanghai ChinaGU Jufang Q U Tiancai Shanghai Iron Steel Research Institute Shanghai China XU Yourong Professor Department of Materials Science Shanghai University of Science Technology Shanghai China 《金属学报(英文版)》1992,5(7):60-64
The dynamic mechanical behaviours of super low carbon high Mo austenitic stainless steel(00Cr20Nil8Mo6CuN)during hot deformation have been studied by using Formaster-Presshot working simulator. The hot deformation equation, as well as the relationship between peakstrain, peak stress and Zener-Hollman parameter, together with the deformation activationenergy have been resulted through the experiments. 相似文献
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H. Y. Leng K. Yang W. X. Han Institute of Metal Research The Chinese Academy of Sciences Shenyang China 《金属学报(英文版)》2000,13(2):465-469
1.ICr25Ni20SiZheat--resiststainlesssteelhasmanyusesbecauseofitsgoodOtidationresistandcormsion--resistpropethesespeciallybecauseitcanwithatthetemperat~Of1150T.ButcracksusuallyoccurduringhotPiercingforitshigh--alloycontentandlargedefonnation--resistforceandbadhotPlashcity.InoldertoimprovetheutiliZationratioofInaterialandsimpledthepcnessofinaldnghigh--alloyedseamlesstube,theauthordevelopedthenewtecboqUeofPrDducingseamlesstubebydefondngelectrDInagneticcentrifugalcasthollowblankll].Thehot--wo… 相似文献
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P.L. Mao ) K. Yang) C. Y. Su) ) Institute of Metal Research The Chinese Academy of Sciences Shengyang China ) School of Metal Material Shenyang University of Technology Shengyang China 《金属学报(英文版)》2001,14(4):285-290
1. Introduction The duplex stainless steels are defined as stainless steels generally consisting of two- phase aggregated microstructure of &ferrite and -y-austenite. Duplex stainless steels have an attractive combination of many excellent properties of single phase, such as high mechan- ical properties, high toughness, high weldablility, excellent corrosion resistance, etc~141. Distributions and morphology of the phases in duplex stainless steels have a great effect on its deformation behavi… 相似文献
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316L不锈钢热加工硬化行为及机制 总被引:2,自引:0,他引:2
在Gleeble-1500热模拟试验机上, 通过高温压缩实验对316L不锈钢的热加工硬化特点和机制进行了研究. 根据Ludwik幂函数模型对实验数据进行了非线性拟合, 并用 Crussard-Jaoul分析法计算了Ludwik幂函数模型的n值. 实验结果表明: 316L不锈钢在热变形过程中易发生加工硬化, 真应力-应变曲线上未出现应力峰值; 热变形过程中发生了部分动态再结晶, 这一不完全的软化机制无法抵消热加工硬化的作用, 另外在热变形过程中发生了孪生行为, 这是热加工硬化的主要机制之一. 相似文献
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18-5-Nb钢中的γ相在室温下处于亚稳状态,室温塑性形变可诱发γ→α马氏体相变,马氏体相变量随形变量而增加。冷塑性形变使18-5-Nb钢抗氯化物SCC性能显著降低,这与钢中γ相的耐蚀性下降有关。在NaCl溶液中,18-5-Nb钢的SCC裂纹以点蚀坑为起源,γ相的选择性腐蚀在点蚀及SCC裂纹的形成和扩展过程中起着重要作用。 相似文献
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ZHAO Pu LU Shiying Central Iron Steel Research Institute Ministry of Metallurgical Industry Beijing China ZHAO Pu Engineer Central Iron Steel Research Institute Ministry of Metallurgical Industry Beijing China 《金属学报(英文版)》1989,2(9):172-176
The SCC susceptibility of the plastically pre-deformed 18-5-Nb duplex stainless steel to lo-calized corrosion was evaluated in both 25% NaCl+1% K_2Cr_2O_7 and 42% MgCl_2 boiling so-lutions.The y phase in the steel is metastable at room temperature and the γ-α′ martensitictransformation can be induced by cold plastic deformation.With the increase in colddeformation,the volume fraction of α′ martensite increases.Cold plastic deformation resultsin a remarkable deterioration of SCC resistance of the steel in chloride-containing solutions,resulting from the decrease in corrosion resistance of γ phase in the duplex.It is indicated that,in NaCl solution,the SCC in 18-5-Nb duplex stainless steel initiates at pits and the selectiveattack on γ phase plays a significant role in the initiation and propagation of SCC. 相似文献