H.B. Wu
,
H.T. Jiang
,
S.W. Yang
,
D. Tang
,
X.L. He
,
null
金属学报(英文版)
Cooled in water after isothermal relaxation of deformed austenite for different times, an Nb-bearing microalloyed steel always exhibits synthetic microstructures, in which bainitic ferrite dominates. Dislocation configurations and distributions of strain induced precipitates inside bainitic ferrite of samples relaxed for different times were distinct. When compared with the austenite model steel, which maintained fcc structure even at room temperature, the strain induced precipitates were not found in the sample without relaxation whereas these were distributed outside dislocations in sample relaxed for 1000s. Most of the strain induced precipitates distribute along dislocations and pin dislocations in sample relaxed for appropriate time. After bainitic transformation, the dislocations formed in deformed austenite remain to be pinned by the precipitates. When these samples were reheated to and held at 650 or 700¡æ, the non-equilibrious microstructures tended to evolve into equilibrious ones. The sample relaxed for 60s displayed the highest thermo-stability, whereas microstructure evolution was the quickest in the sample relaxed for 1000s even though it was the softest prior to reheating. Dislocations inside laths got rid of pinning of precipitates, and their polygonization became the precursor to the evolution of microstructures during reheated and held, followed by gradual disappearance of lath boundaries caused by dislocation climbing. Finally, recrystallization occurred and polygonal ferrite appeared. By hardness measurement, it was found that softening is not a single process occurring during reheated, in which hardness fluctuates with time. There were two peaks in the hardness-time curve of each sample having undergone relaxation, while single peak occured in the curve of the sample not being relaxed. These results indicated that the thermo-stability of microstructures was determined by their history of formation to a considerable degree.
关键词:
bainite
,
null
,
null
,
null
李悦
,
邓爱红
,
刘莉
,
王康
,
谢莎
材料研究学报
利用x射线衍射(xRD)和慢正电子束分析(SPBA)技术研究高温退火后含He钛膜的微观结构和钛膜内He相关缺陷的演化.XRD分析表明,高温退火后Ti和Si在高温下发生反应形成稳定的多晶TiSi2化合物,He原子的掺入会影响TiSi2晶体的择优取向,而对TiSi2晶粒尺寸的影响较小.SPBA结果表明,室温下,钛膜内的缺陷浓度或尺寸会随着掺He浓度的增加而增大;高温退火后,当He浓度小于5％(原子分数,下同)时(除2％外),钛膜内的He相关缺陷浓度随着He浓度增加相应地增加.当He浓度增加到14％时,高温会使较高浓度的He原子、He-空位复合体以及小He泡迁移聚集形成一些尺寸较大He泡,而较大He泡周围与He相关的小尺寸缺陷的浓度则会发生相应地减少.
关键词:
金属材料
,
含He钛膜
,
直流磁控溅射
,
He相关缺陷
,
XRD
,
SPBA
施立群
,
金钦华
,
刘超卓
,
徐世林
,
周筑颖
原子核物理评论
doi:10.3969/j.issn.1007-4627.2005.01.045
研究了用He/Ar混合溅射气体的直流磁控溅射制备钛膜中He的掺入现象.分析结果表明,大量的He原子(He/Ti原子比高达56%) 被均匀地引入到Ti膜中,He含量可由混合溅射气体的He分量精确控制.通过调节溅射参数,可实现样品中He的低损伤引入.研究还发现,溅射沉积的含氦Ti膜具有较高的He成泡剂量和高的固He能力,这可能是溅射沉积形成了纳米晶Ti膜所致.纳米晶Ti膜较粗晶材料具有很高浓度的He捕陷中心,使He泡密度增大而泡尺寸减小.随He引入量的增加,Ti膜的晶粒尺寸减小,He引起的晶体点阵参数和X射线衍射峰宽度增大,晶体的无序程度增加.
关键词:
氦
,
损伤
,
泡
,
钛膜
,
溅射沉积
ZHANG Lei WANG Peixuan TAO Rong MA Ruzhang ZHANG Guoguang University of Science and Technology Beijing
,
Beijing
,
China professor
,
Department of Materials Physics.University of Science and Technology Beijing.Beijing 100083
,
China
金属学报(英文版)
Nucleation and growth of He bubbles at different annealing temperatures T≤1023 K in stain- less steels HR-2 and SS321,implanted with He~+(40-70 keV.1×10~(16)-6× 10~(17) He~+/cm~2),were ohserved under TEM.T=0.45T_m seems to be a transition temperature.The He bubbles continue mainly their nucleation at 0.3T_m< T<0.45T_m,and grow predominantly at T≥0.45T_m,due probably to migration and coalescence by surface diffusion of metal atoms around the bubbles.The apparent activation energies for the growth are found to he 0.41 and 0.31 eV for HR-2 and SS321 respectively.The bubble density in HR-2 is greater than that in SS321 within whole measuring temperature range,and the onset temperature of rapid swelling is also higher.It is believed that the resistance of HR-2 to He is superior to that fo SS321.
关键词:
stainless steel
,
null
,
null
,
null
,
null
钢铁
近日，承钢公司试炼管线钢X70、卷板C700L获成功，钢坯成分、气体含量、铸坯质量等指标均达到标准要求。管线钢X70是具有高强度、高韧性和良好焊接性能的高级别管线。提钒钢轧二厂在总结以往管线钢生产经验的基础上，于4月15日对X70钢组织试制，
关键词:
X70
,
钢种
,
试炼
,
管线钢
,
气体含量
,
铸坯质量
,
焊接性能
,
生产经验
梁平
,
李晓刚
,
杜翠薇
,
陈旭
腐蚀与防护
采用动电位极化和电化学阻抗法研究了X80和X70管线钢在0.5 mol/L NaHCO3+0.02 mol/L NaCl溶液中的腐蚀行为,并通过电容测量方法对其腐蚀机理进行了探讨.结果表明:在0.5 mol/L NaHCO3+0.02 mol/L NaCl溶液中,X80管线钢的点腐蚀电位Epit比X70钢的要正一些,发生点腐蚀的倾向性更小.Mott-Sehottky分析表明:X80比X70管线钢表面钝化膜内的施主密度更低,缺陷数量更少,从而减少了点腐蚀萌生的潜在位置,使X80钢比X70钢具有更好的耐点蚀性能.
关键词:
X80管线钢
,
点蚀
,
莫特一肖特基分析
谢莎
,
邓爱红
,
王康
,
王玲
,
李悦
,
王勇
,
汪渊
材料研究学报
用磁控溅射方法制备纳米多晶钨膜,采用x射线衍射(XRD),扫描电子显微镜(SEM),弹性反冲探测(ERD)和慢正电子束分析(SPBA)等手段研究了在高能He+和H+依次对其辐照后He相关缺陷对H滞留的影响.结果表明,注He+钨膜在退火后从β型钨向α型钨转变；钨膜中的He含量随着退火温度的提高而减少,在873 K退火加剧钨膜中He原子的释放,且造成钨膜空位型缺陷的增加和结构无序度的提高；钨膜中的H滞留总量随着He滞留总量的减少略有下降.
关键词:
金属材料
,
磁控溅射钨膜
,
慢正电子束分析
,
H
,
He
黄本生
,
陈鹏
,
张荣副
,
龚成龙
,
苑评
,
代丽
,
胡梦笛
材料导报
doi:10.11896/j.issn.1005-023X.2016.06.024
采用手工钨极氩弧焊和电弧焊实现了316L/X65双合金复合管的对接焊接.为了研究复合管的焊接工艺,对焊接接头进行了硬度、拉伸和冲击测试,利用光学显微镜、扫描电镜和能谱仪分析了接头的微观结构和成分特点,并对接头进行了电化学实验.结果表明:复合管焊缝由碳钢层、扩散层、过渡层和不锈钢层组成,碳钢层主要为针状铁素体,扩散层出现了马氏体组织,过渡层和不锈钢层焊缝中铁素体呈骨架或蠕虫状分布在奥氏体晶界;本实验焊接工艺下,覆层未受到碳钢层的稀释,化学成分与母材基本一致,但耐蚀性略有降低;焊接接头各项力学性能良好.
关键词:
316L/X65
,
复合管
,
焊接工艺
,
显微组织
,
性能
邓洪达
,
曾顺鹏
腐蚀与防护
doi:10.11973/fsyfh-201508007
海洋天然气输送用复合金属管内外层因内层金属输送介质渗漏将构建电偶对,加速外层金属腐蚀.本工作采用浸泡试验和电化学技术分析X65-316L电偶对在模拟产出水中的电偶腐蚀行为.采用SEM观察电偶对金属腐蚀前后形貌变化;分析X65和316L偶接前后开路电位(OCP)和偶接电流密度(Jcc)随时间的变化曲线,以及其对电化学参数的影响.结果显示,X65-316L电偶对在模拟产出水中X65为阳极,316L为阴极;与偶接前相比,X65腐蚀速率增加,316L腐蚀速率下降,同时X65阴极极化率减小,316L阳极极化率增加.
关键词:
复合管
,
电偶腐蚀
,
SEM
,
电化学技术
Z.Y. Wu
金属学报(英文版)
The Si L2,3 X-ray absorption near-edge structure (XANES) can be used to probe thelocal structure around Si and derive electronic information of the unoccupied s- andd-like partial density of states in nano-size SiO2. We present Si L2,3-edge for threedifferent size silicates acquired by total electron yield (TEY) at the photoemission sta-tion of Beijing Synchrotron Radiation Facility (BSRF). The Si L2,3-edge spectra areinterpreted based on ab initio full multiple-scattering (MS) calculation. The Si L2.3-edge of nano-size materials has XANES similar to that of a-quartz. The similaritiesbetween the Si L2.3-edge shapes attest to a common molecular-orbital picture of theirSi-O bonding and the same coordination state. However, a considerable broadeningof Si L2,3-edge XANES spectra as decrease of particle size is also an indicative ofpolyhedral distortions.
关键词:
multiple scattering calculation
,
null
,
null
,
null
