赵新兵
,
K.LüCKE
金属学报
传统的计算三维晶粒尺寸分布函数(3D SDF)的方法大多基于S模型,从而导致极大的系统误差,其根源在于模型中的球状晶粒假设不符合实际晶粒组织特征,本文建立了基于多面体晶粒假设的A模型,并给出了相应的概率函数表达式及计算方法,理论分析及实验检验结果表明,A模型基本上消除了系统误差,显著地提高了计算精度,是一个较理想的几何模型。
关键词:
晶粒尺寸
,
grain size distribution
,
stereology
,
geometric model
张志波
,
张红斌
,
张瑜
,
杨春雷
,
张卫强
,
李金柱
钢铁
研究了在昆钢特有的双机架紧凑式炉卷轧机上开发和生产高强度汽车大梁钢K610L的工艺。通过合理的Nb-Ti复合成分设计和各工序生产工艺试验与优化,生产出满足重型载货汽车制造厂要求的K610L高强度汽车大梁钢。结果表明,昆钢利用炉卷轧机生产的K610L具有较高的抗拉强度、良好的韧性、优异的冷弯成型性能和较好的自然时效性。
关键词:
炉卷轧机
,
高强度汽车大梁钢
,
Nb-Ti复合
吴家晖
,
郭颖
,
邓夏
,
方艺斌
硅酸盐通报
通过照度实验,基于CIE1976L*a*b*均匀色空间研究照度对锰铝榴石颜色评价的影响.照度增加,锰铝榴石黄色的明度L*显著增加,且自身明度较低的锰铝榴石黄色明度更易受照度变化的影响.△a*平均为17.30,△b*平均为36.83,明显大于△a*的均值,表明照度对锰铝榴石黄色调的影响更大;当照度较低时,彩度C*与照度呈正相关,当照度超过227.73 lx后,C*将不再增大或与照度呈负相关;色调角h0随照度增加而增大,平均色调角增量△h0=11.59,增幅较明度和彩度小.同时验证Stevens效应、Hunt效应、Helmholtz-Kohlrausch效应、Bezold-Brücke色相偏移理论在锰铝榴石颜色观察上的体现.此外,当明度差值DL* ＞15时,DL*与色差DE2000呈正相关且相关性最大,说明明度对色差具有最大贡献.得出结论,照度影响锰铝榴石的明度、彩度、色相,间接影响色差,其中对明度影响最直观,故在质量评价时应严格控制照度标准.
关键词:
锰铝榴石
,
照度
,
颜色
,
均匀色空间
,
质量评价
NI Hongwei
,
HE Hang
,
LI Guangqiang
,
LIU Jing
钢铁研究学报(英文版)
Preparation of nanocrystalline 430L stainless steel by both highenergy ball milling and spark plasma sintering technique has been investigated. The results have shown that the hardness can be improved markedly with an increase in sintering temperature and holding time. The lower the apparent porosity of nanocrystalline 430L stainless steel, the higher is the Vickershardness. The tensile strength reached a maximum value of 713 MPa when the sample was sintered at 1 173 K for 10 min, and then it evidently decreased with an increase in sintering temperature and holding time because of the growth of crystalline grain.
关键词:
ferritic stainless steel;nanocrystalline;spark plasma sintering
尹晓燕
,
初乃波
,
赵庆宇
,
王金渠
,
鲁金明
硅酸盐通报
采用水热合成法成功合成出高结晶度的L沸石.合成初始凝胶(物质的量)组成为5.4K2O:5.7Na2O:1Al2O3:30SiO2:500H2O,反应温度为175℃,反应时间为24 h.采用X射线衍射(XRD)、扫描电镜(SEM)对合成的沸石分子筛进行了表征.XRD检测结果表明:制备的沸石具有L沸石典型特征峰,结晶度较高.SEM检测结果表明:合成的L沸石分子筛呈圆柱状,粒径约为1 μm,大小均匀.由于L沸石晶化区间相对狭窄,合成过程中须严格控制反应条件,所以又全面考察了水热合成条件对L沸石晶化的影响,结果表明:nSiO2/nAl2O3、Nh2o/n(Na2O+K2O)、nNa2O/n(Na2O+K2O)对结晶过程影响很大;陈化可以较好地减小晶粒尺寸,增加晶粒均匀度.
关键词:
L沸石
,
水热合成
,
晶化
梁成浩
,
郭承忠
材料保护
doi:10.3969/j.issn.1001-1560.2007.10.007
采用正交试验法对无氰电镀22K金工艺进行了优选,并利用X射线荧光光谱仪、分光色彩精灵、金相显微镜、显微硬度计等检测了镀层表面的金含量、表面光泽度、表面形貌及镀层厚度、显微硬度等性能.结果表明,无氰电镀22 K金优化的工艺参数:160 g/L亚硫酸钠,120 g/L柠檬酸钾,30 g/L硫酸钴,9 g/L亚硫酸金钠(以金计),40～50 g/L磷酸氢二钾,10 g/L添加剂A,施镀温度45～55℃,阴极电流密度0.18～0.25 A/dm3,pH值8.5～9.5,阴、阳极面积比1:3,搅拌方式为阴极移动.在优化工艺下所得的22K金镀层呈金黄色、均匀、细致、半光亮,具有较好的结合力、耐蚀性和较高的显微硬度,可作装饰性镀层.
关键词:
无氰
,
电镀
,
金合金
,
22K金
,
工艺
Zhong CHU
材料科学技术（英文）
Simulations are performed on temporal evolution of atom morphology and ordering parameters of Ni-14.5 Cr-16.5 Al alloy during early precipitation process at different temperatures based on microscopic phase-field theory; the relationship between precipitation sequence and mechanism of L12 and D022 structure and precipitation temperature are illuminated. The nonstoichiometric ordered L12 phases appear first with congruent ordering+spinodal decomposition mechanism which is then followed by precipitation of D022 phases at ordering domain boundaries of L12 phases by spinodal decomposition mechanism at 1073 K and 1223 K. The nonstoichiometric L12 phases transform to stoichiometric ordering phases gradually. The incubation period of L12 and D022 phases is shorter at 1073 K than that 1223 K, and growth speed is higher at 1073 K. At 1373 K, L12 and D022 phases appear simultaneously by non-classical nucleation and growth mechanism. After that the particles of D022 phases diminish and disappear gradually; L12 phases grow and single L12 phases are remained at last.
关键词:
Ni-Cr-Al
,
微观相场
,
沉淀
,
序参数
,
模拟
