欢迎登录材料期刊网

材料期刊网

高级检索

  • 论文(82)
  • 图书()
  • 专利()
  • 新闻()

STRUCTURAL CHANGE IN HEAT AFFECTED ZONE AND ITS INFLUENCE ON PROPERTIES OF WELDED WHITE CAST IRON

ZOU Zengda WANG Yong REN Dengyi Shandong Polytechnic University , Jinan , China

金属学报(英文版)

The structural change in heat affected zone(HAZ)and its influence on properties of welded white cast iron have been investigated by means of thermal cycle simulation technique.The structure of the white cast iron at peak temperature 800℃ was examined as cementite in pearlitic matrix,of which the hardness and impact toughness are the lowest,while the struc- ture after cyclic heating at high peak temperature is mainly cementite together with twin martensite,of which the hardness and impact toughness are rather higher.The phase bounda- ries in the structure of low hardness are smooth and regular as well as with fine precipitates. Both the cleavage and interphase fracture were revealed in the structure of low hardness,while the transgranular fracture was found in those areas of higher hardness.

关键词: white cast iron , null , null

两种组织的Ren80高温合金的蠕变裂纹扩展行为

孙坚 , 张源虎 , 胡赓祥

金属学报

研究了定向凝固和普通铸造的Ren80合金在1123K静载荷下的蠕变裂纹扩展行为结果表明,Ren80合金蠕变裂纹扩展速率,可用应力强度因子较好地关联定向凝固合金蠕变裂纹与扩展速率较低,其应力强度因子指数约为普通铸造合金的1/2

关键词: 高温合金 , directional solidification , stress intensity factor , creep crack propagation , null

Two-step magnetization in a spin-chain system on the triangular lattice: Wang-Landau simulation

Physical Review B

The Wang-Landau algorithm is used to study the thermodynamic and magnetic properties of triangular spin-chain system based on two-dimensional Ising model in order to understand the magnetic-order dynamics in Ca(3)Co(2)O(6) compound. The calculated results demonstrate that the equilibrium state of the rigid spins produces the two-step magnetization curve at low temperature even when the random-exchange term is considered. This work indicates that the four-step magnetization behavior observed experimentally must be due to the nonequilibrium magnetization.

关键词: calcium compounds;exchange interactions (electron);Ising model;magnetisation;thermodynamics;one-dimensional ca3co2o6;density-of-states;compound ca3co2o6;phase-diagram;proteins;crystal

PM René 95合金涡轮盘等温锻造工艺的模拟式设计

张麦仓 , 董建新 , 曾燕屏 , 谢锡善 , 罗子健

金属学报

利用热力耦合有限元程序FORMT,对PM René 95合金中等尺寸(外径尺寸约为630 mm)涡轮盘的等温锻造工艺进行了模拟式设计.结果表明,采用TZM钼基合金模具,在1050℃以接近10-3s.的应变速率进行闭式模锻和开式模锻,模具材料均能满足使用要求,且开式模锻设备最大载荷不超过31×103kN;采用K21合金模具,在1000℃以相同条件等温成形,模具材料因变形热效应及边界摩擦引起温升而失效且所需设备吨位相对较大.

关键词: PM , null , null , null

PM René 95合金涡轮盘等温锻造工艺的模拟式设计

张麦仓 , 董建新 , 曾燕屏 , 谢锡善 , 罗子健

金属学报 doi:10.3321/j.issn:0412-1961.2002.10.022

利用热力耦合有限元程序FORMT,对PM René 95合金中等尺寸(外径尺寸约为630 mm)涡轮盘的等温锻造工艺进行了模拟式设计.结果表明,采用TZM钼基合金模具,在1050℃以接近10-3s.的应变速率进行闭式模锻和开式模锻,模具材料均能满足使用要求,且开式模锻设备最大载荷不超过31×103kN;采用K21合金模具,在1000℃以相同条件等温成形,模具材料因变形热效应及边界摩擦引起温升而失效且所需设备吨位相对较大.

关键词: PM René 95合金,等温锻造,热力耦合有限元,模拟式工艺设计

电渣重熔连续定向凝固René88DT合金的组织与热变形行为

付锐 , 陈希春 , 任昊 , 冯涤

航空材料学报 doi:10.3969/j.issn.1005-5053.2011.3.002

自行设计开发了适合工业化生产高纯净,低偏析,无宏观缺陷铸锭的电渣重熔连续定向凝固技术(ESR-CDS)的设备和工艺,利用该技术成功制备了直径为φ150mm的René88DT合金定向凝周铸锭.采用XRD测试了定向凝固柱状晶的生长取向,结果表明,ESR-CDS René88DT铸锭柱状晶择优生长方向为<100>系晶向;ERS-CDS铸锭与传统ESR铸锭相比,枝晶组织生长方向保持一致,二次枝晶臂均匀细小,元素偏析程度低,且晶间一次析出相呈颗粒状,尺寸细小;等温热压缩实验结果表明,ESR-CDS René88DT合金热压缩试样在1100℃,0.0-50.1s-1应变速率下可达到70%以上压缩变形量并获得均匀细小的动态再结晶组织;ESR-CDS René88DT合金铸锭经等温锻造制备出了φ170mm×73mm的饼坯件,锻压变形量超过70%,饼坯件除上下两端的变形死区外均发生了动态再结晶,晶粒尺寸约50μm.

关键词: 电渣重熔连续定向凝固 , 热变形 , 动态再结晶

疲劳保载时间与固溶处理对PM René 95合金高温裂纹扩展速率的影响

李晓 , 董建新 , 张丽娜 , 张麦仓 , 胡尧和 , 谢锡善 , 国为民

金属学报

经不同固溶时效处理的PM René 95合金于650℃分别在蠕变、保载5和90 s疲劳载荷条件下进行了裂纹扩展速率实验.结果表明,相同热处理制度下,疲劳保载时间越长,裂纹扩展速率越高;相同载荷条件下,增加一次高温固溶并缓冷,有利于降低合金的裂纹扩展速率,且固溶温度越高裂纹扩展速率越低;1200℃一次固溶缓冷并于1160℃二次固溶热处理比1140℃一次固溶的裂纹扩展速率约降低一个数量级;基体晶粒尺寸适当加大,强化相粒子γ′c数量增加、形状趋于田字形,有利于降低裂纹扩展速率.

关键词: René , null , null

疲劳保载时间与固溶处理对PM René 95合金高温裂纹扩展速率的影响

李晓 , 董建新 , 张丽娜 , 张麦仓 , 胡尧和 , 谢锡善 , 国为民

金属学报 doi:10.3321/j.issn:0412-1961.2001.10.012

经不同固溶时效处理的PM René 95合金于650℃分别在蠕变、保载5和90 s疲劳载荷条件下进行了裂纹扩展速率实验.结果表明,相同热处理制度下,疲劳保载时间越长,裂纹扩展速率越高;相同载荷条件下,增加一次高温固溶并缓冷,有利于降低合金的裂纹扩展速率,且固溶温度越高裂纹扩展速率越低;1200℃一次固溶缓冷并于1160℃二次固溶热处理比1140℃一次固溶的裂纹扩展速率约降低一个数量级;基体晶粒尺寸适当加大,强化相粒子γ′c数量增加、形状趋于田字形,有利于降低裂纹扩展速率.

关键词: René 95粉末高温合金,裂纹扩展速率,热处理

天然气井油管悬挂器腐蚀失效分析

刘守平 , 周上祺 , 王佳眉 , 任勤

腐蚀科学与防护技术

用金相显微镜、扫描电镜、X射线衍射仪和X射线能谱仪对天然气井油管悬挂器腐蚀失效进行了检测分析,并对天然气井油管悬挂器用35CrMo钢进行了盐雾试验,结果表明,天然气中的水和CO2是引起腐蚀的主要介质,腐蚀产物主要是FeCO3,高速天然气冲刷和钢中的非金属夹杂加剧了腐蚀的速度. CORROSION FAILURE ANALYSIS OF AN OIL TUBE USED IN NATURAL GAS WELL LIU Shou-ping,ZHOU Shang-qi,WANG Jia-mei,REN Qin Chongqing University A failed oil tube used in natural gas well was examined by optical microscope,scanning electron microscope ,X-ray diffractometer and X-ray spectrometer.Corrosion behavior of 35CrMo steel samples of the oil tube were investigated by means of salt spray tests in the laboratory.The results show that CO2 and H2O are primary factors in the corrosion of oil tube.The corrosion product is FeCO3,non-metallic inclusions in the steel and erosion of natural gas fluid played an important role in accelerating the corrosion. oil tube; natural gas well; 35CrMo steel; failure analysis; corrosion

关键词: 悬挂器 , null , null , null

  • 首页
  • 上一页
  • 1
  • 2
  • 3
  • 4
  • 5
  • 下一页
  • 末页
  • 共9页
  • 跳转 Go

出版年份

刊物分类

相关作者

相关热词