Ce对00Cr17高纯铁素体不锈钢再结晶及晶粒长大的影响

利用显微硬度计、金相显微镜、差热分析仪和XRD研究了稀土元素Ce对00Cr17高纯铁素体不锈钢再结晶及晶粒长大的影响.结果表明,00Cr17钢中加入Ce降低了再结晶温度,促进了再结晶的发生.主要是由于微量Ce固溶到00Cr17钢中引起晶格畸变,增加了冷变形储存能,从而增大了00Cr17钢的再结晶驱动力.00Cr17钢中加入Ce增加了晶粒长大激活能,减小了晶粒生长指数,阻碍了00Cr17钢的晶粒长大,这是由于Ce偏聚到晶界,增大晶界运动的阻力.     

微合金化钢的动态再结晶及其显微组织的研究

应用Ｇｌｅｅｂｌｅ－１５００热模拟试验机测定了微合金化钢在不同终轧温度下的真应力－－真应变曲线,研究了终轧温度及微合金元素含量对动态再结晶的影响,研究结果表明,Ｖ,Ｎｂ可显著抑制微合金化钢轧制过程中形变奥氏体的动态再结晶,因此,在较高的终轧温度下,仍能得到细小而均匀的显微组织。     

Kinetics for static recrystallization after hot working of 0.38C-0.99Cr-0.16Mo steel

The restoration mechanisms for static reerystallization of work-hardened austenite were investigated by using double-pass compression tests performed on medium-carbon steel containing chromium and molybdenum. The softening fraction was defined by 2% offset method. The results show that Avrami exponent of about 0.21 is insensitive to deformation temperature, indicating that the action of steel grade should be considered. The time of 50% recrystallization (t0.5) decreases noteworthily with the increase of deformation temperature. Apparent activation energy for static recrystallization of 195 kJ/mol, which is close to that of vanadium microalloyed steel, is obtained by calculating. The increasing trend of the driving force for recrystallization is opposite to that of the deformation temperature, which is attributed to the number of operative slip system increasing as temperature increasing.     

氧化物弥散强化合金的再结晶行为及强化机理的研究

运用光学显微镜测量了ODS(Oxide Dispersion Strenghtened)合金的晶界迁移速度,并计算了再结晶激活能.再结晶温度测量结果表明,PM2000的再结晶温度为720 ℃,与传统金属材料的再结晶温度(0.4～0.6 Tm)的规律一致.TEM分析显示,再结晶后的晶粒呈高长径比的柱状晶,再结晶过程中晶界前沿受到颗粒的钉扎.ODS合金基体中的位错被颗粒钉扎在脱钉侧,表现出相互吸引的作用方式,因而认为颗粒/位错相互吸引机理是ODS合金强化的原因.     

微合金元素对重轨钢动态再结晶及其显微组织的影响

应用Gleeble-1500D热模拟试验对重轨钢进行单道次压缩实验,测定不同终轧温度下的真应力-真应变曲线,并用扫描电镜观察变形后空冷的显微组织,研究不同终轧温度和微合金元素V,Nb和Re对重轨钢动态再结晶及显微组织的影响.结果表明,V,Nb和Re能显著地抑制形变奥氏体的动态再结晶.在终轧温度较高时仍能得到细小均匀的显微组织.     

The Effects of Aging Precipitation on the Recrystallization of CuNiSiCr Alloy

The interaction between precipitation and recrystallization and its effect on the properties of the Cu-Ni-Si-Cr alloy during aging were discussed. The results show that the deformation results in much more dispersed precipitation of the phases. The precipitations have accelerating or retarding effects on the recrys allization. On the formation and growth of recrystallization, the precipitated phases are coarsed or dissolved in front of grain boundaries following a re-precipitation in the recrystallization area.     

稀土对4145H钻铤钢动态再结晶的影响

应用Geeble-1500D热模拟试验机分别对稀土含量为6×10-6和16×10-6的钻铤钢进行单道次压缩实验,测定其不同终轧温度下的真应力-真应变曲线,采用应变速率0.01 s-1,变形量60%,终轧温度为850,950,1050,1150℃,研究不同稀土含量,不同终轧温度对钻铤钢再结晶的影响。结果表明,稀土含量为16的钻铤钢能显著地抑制形变奥氏体的动态再结晶。     

铌对弹簧钢60Si2MnA动态再结晶的影响

在Gleeble-1500热模拟实验机上研究含铌弹簧钢的动态再结晶行为,用透射电镜对铌的析出物进行观察,并分析铌对弹簧钢动态再结晶的影响。结果表明,含铌弹簧钢易发生动态再结晶,在温度为850-1050℃、变形速率为0.1-20 s^-1条件下均发生动态再结晶;在变形速率为5 s^-1的条件下,60Si2MnA动态再结晶的发生推迟50℃左右;在低温情况下,铌推迟60Si2MnA动态再结晶的主要原因是Nb（C,N）的析出及其钉扎作用。     

CSP薄板冷轧退火组织和织构的研究

采用EBSD分析方法,对CSP试验钢冷轧板退火过程中组织转变和再结晶织构的演变进行分析,结果表明,在退火过程中,α取向线上的{112}<110>和{110}<110>织构的取向密度基本上没有变化,{100}<110>织构的取向密度是逐渐降低的,而{111}<110>织构有所增强,γ取向线上{111}<011>和{111}<112>织构都是呈先降低后升高的趋势,而且最终{111}<011>和{111}<112>两种织构的取向密度趋于相等,分别为5.28和5.24.     

超低碳贝氏体钢形变奥氏体静态再结晶行为研究

在MMS-200热模拟试验机上进行了双道次热压缩变形实验,研究了超低碳贝氏体钢的静态再结晶软化规律.利用应力补偿法（0.2%）计算了不同形变温度下的静态再结晶软化率。试验结果表明：形变温度和形变道次间隔时间对超低碳贝氏体钢的静态再结晶行为影响非常大。根据相关试验数据以及静态再结晶动力学方程,经计算得出超低碳贝氏体钢的静态再结晶激活能为292.42 kJ/mol。     

再结晶退火温度对无取向硅钢织构和磁性能的影响

对冷轧及退火后无取向硅钢织构及磁性能的变化进行研究。借助电子背散射衍射（EBSD）技术测量退火试样的极图,计算取向分布函数（ODF）和织构组分的体积分数,并利用TYU-2000M磁性能测量仪测量试样的磁性能。结果表明,810、840、880℃下退火3min后,试样的再结晶均充分完成,且晶粒随着退火温度的升高而长大;退火后,试样中首先显现{111}〈112）织构组分,且随退火温度的升高呈增强趋势;退火温度继续升高时,{111}〈110〉织构组分增强,一次再结晶后材料中出现{111}面织构,导致试样的磁感应强度B50降低,同时由于晶粒的长大使得试样的铁损P15减小。     

09CuPTiRE钢动态再结晶的热模拟实验与有限元模拟

以热模拟实验为基础，建立09CuPriRE钢的动态再结晶模型．应用有限元软件DEFORM模拟热压缩变形并提取模拟信息，编程实现动态再结晶体积百分数分布的可视化．模拟结果表明，增大变形量、提高变形温度以及减小变形速率，都能促进动态再结晶发生，其中变形量及变形温度影响显著．这与实验曲线反映的特征相符，从而证明了模型及模拟的有效性．     

基于偏好多目标优化和遗传算法的输电网架重构

提出一种基于偏好多目标优化和遗传算法的输电网架重构方法,考虑对于不同优化目标的偏好,制定网架重构方案。计及系统中机组、线路以及负荷的影响,提出3个评价指标作为优化目标,构建一个偏好多目标优化模型。考虑到所建优化模型的偏好性和离散性,提出一种基于偏好的非支配排序遗传算法。提出基于偏好的支配关系、种群规模控制技术以及重复个体过滤技术,用于提高算法的效率,获得解数目可控的偏好Pareto最优解集。仿真结果表明,所提模型能够有效平衡网架重构的不同影响因素,所提算法对于网架重构优化问题有较高的求解效率。     

Texture evolution of commercial pure Ti during cold rolling and recrystallization annealing

X-ray diffraction (XRD) was employed to analyze the texture evolution of commercial pure (CP) Ti during cold rolling and re-crystallization annealing. The texture components were measured by electron backscattered diffraction (EBSD) after recrystallization an-nealing. The CP Ti tends to form a texture with the basal pole tilted 30°-40° away from the normal direction toward the transverse direction. The texture of the initial hot-rolled plate can be classified into three kinds, i.e., the pyramid texture and , the basal plane texture , and the stronger prism texture . After cold rolling and annealing (700°C, 60 min), the main texture components are the cold-rolled texture and the recrystallized texture . The texture is in-herited from the texture of the initial hot-rolled plate with the decrease of orientation density gradually. The volume contents of the cold-rolled texture and the recrystallized texture are calculated by EBSD. After recrystallization annealing, the specimen is rich in the recrystallized texture and inherits some of texture components from the cold-rolled texture. When the annealing time is prolonged, the anisotropic value decreases.     

预先再结晶对冷轧双相钢组织性能的影响

通过实验研究了预先再结晶对冷轧双相钢组织性能的影响。首先通过研究再结晶演变规律确定了预先再结晶的温度和时间分别为700℃保温30s;另外,通过奥氏体形成动力学及相变点检测确定两相区退火工艺参数;最后分析了预先再结晶对冷轧双相钢组织性能的影响。实验表明：冷轧钢板经T=700％,t=308预先再结晶处理后,迅速升温进入双相区热处理可以较好的消除了条带状组织,得到均匀的F＋M双相组织,其塑性有了较大幅度的提高,抗拉强度略有上升。     

Effects of Antihepatocarcinoma with Apatite Nanoparticles in vivo

The inhibition effect of hydroxyapatite （ HAP ） nanoparticles on hepatocarcinoma was investigated in vivo. The human hepatocarcinoma cell line Bel- 7402 was transplanted subcutaneously into nude mice. Hydroxyapatite nanoparticles suspension at a dose of 0. 2 mL was injected into the transplanted tumors every day for 2 weeks, and saline was used us control. The efficacy of hydroxyapatite nanoparticles on this carcinoma was surveyed and morphological changes of tissue and cells were observed by light microscopy and transmission electron microscopy （TEM）. Experimental results show that hydroxyapatite nanoparticles have a visible destructive effect on the structures of hepatocarcinoma cells and tissue. The inhibition rates of tumor growth were 77.21% and 51. 32% after intra-tumor injection of hydroxyapatite nanoparticles for 1 week and 2 weeks, respectively. Compared with the control group, hydroxyapatite nanoparticles can also prolong the survival time of the nude mice bearing this cancer significantly. This indicates that hydroxyapatite nanoparticles have the therapeutic potential on hepatoma in vivo.     

Effect of Nb on the dynamic recrystallization behavior of high-grade pipeline steels

The dynamic recrystallization(DRX)behavior oflugh-grade X80/X100 pipeline steels with different Nb contents was investigated through single pass compression experiment using a Gleeble 1500 thermomechanical simulator.By the regression of stress-strain data obtained in the experiment,the deformation activation energy of DRX was identified,and the critical strain was calculated with the Poliak-Jonas (P-J)method.Based on the analysis,the occurrence condition and kinetics of DRX were determined.The results show that as the Nb content increases from 0.08wt% to 0.095wt%,the activation energy ofrecrystallization raises from 365 to 395 kj/mol.The critical strain of DRX can be determined more accurately by the P-J method,and the ratios of critical strain to peak strain of X80 and X100 pipeline steels are 0.51 and 0.49,respectively,which are similar to the results achieved by other researchers and calculated with empirical formulae.     

Research on microstructural evolution and dynamic recrystallization behavior of JB800 bainitic steel by FEM

Single pass compression tests were conducted on Gleeble1500 thermal simulator. The effect of different deformation parameters on the grain size of dynamically recrystallized austenite was analyzed. A mathematical model of dynamic recrystallization and a material database of JB800 steel, whose tensile strength is above 800 Mpa, were set up. A subprogram was compiled using Fortran language and called by Marc finite element software. A thermal coupled elastoplastic finite element model was established to simulate the compression process. The grain size of recrystallized austenite obtained by different recrystailization models was simulated. The results show that the optimized dynamic recrystallization model of JBS00 bainitic steel has a higher precision and yields good agreement with metallographic observations.     

Effects of the interaction between hydroxyapatite nanoparticles and hepatoma cells

To gain a better understanding of the anticancer effects of hydroxyapatite(HAP) nanoparticles in vivo and in vitro, the effects of the interaction of HAP nanoparticles with hepatoma cells were explored. HAP nanoparticles were prepared by homogeneous precipitation and characterized by laser particle analysis and transmission electron microscopy(TEM). HAP nanoparticles were observed to be uniformly distributed, with rod-like shapes and diameters in the range of 42.1-87.1 nm. Overnight attached, suspended, and proliferating Bel-7402 cells were incubated with HAP nanoparticles. Inverted microscopy observation revealed that HAP nanoparticles with a cell membrane showed good adsorption. TEM demonstrated that HAP nanoparticles were present on the surface of cells, continuously taken up by cells through endocytosis, and transported in vesicles close to the nucleus. Fluorescence microscopy showed that the concentrations of intracellular Ca2+ labeled with Fluo-3 calcium fluorescent probe were significantly enhanced. In addition, inverted microscopy observation revealed that suspended cells treated with HAP nanoparticles did not adhere to the culture bottle, resulting in cell death. After the overnight attached cells were treated with HAP nanoparticles for 96 h with increasing doses of HAP nanoparticles, inverted microscopy observation revealed that cell proliferation was slowed and cell–cell adhesion was weakened. Feulgen staining and image analysis indicated that the nuclear DNA content of the cells was markedly reduced, and argyrophilic nucleolar organizer region(AgNOR) staining and image analysis indicated that the number of AgNORs was signifi cantly decreased. Therefore, hepatoma cells brought about the adsorption, uptake, transport and degradation of HAP nanoparticles. In addition, HAP nanoparticles affected hepatoma cells with regard to cell–cell adhesion, cell and extracellular matrix adhesion, and DNA and protein synthesis; thus inhibiting cell proliferation. This understanding of the effects of interaction between HAP nanoparticles and hepatoma cells is useful for further study of the anticancer mechanisms of HAP nanoparticles.     

基于元胞自动机方法的CSP流程冷轧低碳钢再结晶过程的模拟研究

采用元胞自动机方法对CSP流程冷轧低碳钢再结晶过程进行模拟研究。结果表明,冷轧变形量为71.4%的CSP流程冷轧低碳钢的再结晶开始温度为540℃左右,再结晶结束温度为600-620℃;计算机模拟得到再结晶完成温度为604℃,再结晶完成时间为96 min;再结晶完成时,其晶粒平均直径为7.0μm,而晶粒尺寸分布主要集中在2-14μm,此类尺寸晶粒约占晶粒总数的90%,且具备了Weibull分布函数的特征。同时冷轧低碳钢再结晶完成时,{111}〈110〉和{111}〈112〉织构组分的含量最高,总计为63.12%,{110}〈110〉和{112}〈110〉织构组分的含量则分别为9.67%和7.6%,而{001}〈110〉织构组分的含量最低。