On the study of the f.c.c.-h.c.p. martensitic transformation using a diffraction approach—II. H.c.p. → f.c.c. transformation

Theory of diffraction from h.c.p. crystals undergoing martensitic transformation to the f.c.c. structure through a non-random insertion of deformation faults is developed. From a comparison of the theoretically predicted diffraction effects with those experimentally observed on single crystals of ZnS, it is shown that the thermally induced transformations in this material are growth controlled while the deformation induced transformation is nucleation controlled.     

On the study of the f.c.c.-h.c.p. martensitic transformation using a diffraction approach—I. F.c.c. → h.c.p. transformation

A new approach based on diffraction evidence for the involvement of shear at the atomic level is proposed to elucidate the mechanism of the f.c.c. to h.c.p. martensitic transformation. This approach is based on the analysis of the intensity distribution along streaked reciprocal lattice rows observed on diffraction patterns recorded from partially transformed f.c.c. crystals. The relevant theory of diffraction from crystals undergoing f.c.c.-h.c.p. transformation by non-random insertion of deformation faults is developed. This approach, as distinct from the conventional microstructural approach, can be especially useful in situations where the transformation strains are self accommodating in nature, such that there is no observable surface relief effect.     

D.D.S.控制剪切机

在武钢硅钢片厂的联合剪切机组中,使用了D.D.S.控制的下切式斜刃剪。剪切时,连续地供给带钢,由D.D.S.数字直流伺服系统控制,自动地剪切成所需长度。尽管D.D.S.剪切机是启动工作制的不连续剪切,但它具有飞剪的电控能力和高精度定尺公差的控制,而且结构又很简单。不仅适用于新设备的设计,尤其适用于旧设备的改造。     

T.R.T.的推广应用前景

本文对国内外Ｔ．Ｒ．Ｔ装置的历史发展，技术现状和应用情况以及国内未来的市场前景作了综合介绍，并举例就该技术的适用性和经济性进行了比较系统的分析。     

E.O.F.炼钢法现状

自1978年以来一直在15～250t平炉上成功地进行着钢液面下的水平吹氧。熔池液面下吹氧也是能源最佳化炉的主要特征。 1982年春季在巴西Korf分公司资助下潘斯黑色冶金公司(C.S.P.)投产了一台25t E.O.F.(Energy Optimizing Furnace)试验装置,并于1982年8月在克尔(西德)介绍KR法时首次报道了它的结果。1982年12月以来在C.S.P.卓有成效地     

The role of structural ledges at phase boundaries—III. F.C.C.-B.C.C. interfaces in Kurdjumov-Sachs orientation

The ledge mode of misfit accommodation is extended to {111} f.c.c.∥{110} b.c.c. interfaces with the Kurdjumov-Sachs (KS) orientation relationship. As with the Nishiyama-Wassermann (NW) relationship the geometric quantities are uniquely related by the misfit ratio r of atomic diameters. A rigid lattice analysis shows that the driving forces for a KS orientation relationship are significantly larger than those for the NW-x and even more so than those for the NW-y relationships. The rigid analysis also predicts that the terrace width which satisfies the periodicity conditions for a stepped interface are well within the terrace widths which allow significant energy gains. The models developed for the NW analysis are modified for KS configurations and employed to sum energies for the terrace patches, tilt misfit dislocations and the riser interface energy. Comparing this energy with that of a planar interphase boundary comprised of only misfit compensating dislocations shows that a stepped interphase boundary is energetically favored at r values near and greater than r_KS but less than r_NW-y.     

Kinetics of F.C.C. → B.C.C. heterogeneous martensitic nucleation—I. The critical driving force for athermal nucleation

Employing available experimental data for athermal f.c.c. → b.c.c. martensitic transformation in binary, ternary and multicomponent Fe-base alloys, a model is developed and tested for the critical driving force at the M_s temperature. Incorporating the theory of solid solution hardening, we describe the composition dependence of the athermal frictional work for martensitic interface motion governing the kinetics of barrierless heterogeneous nucleation. The available data suggests that the composition dependence of the athermal frictional work is of the same form as that for slip deformation. We have evaluated the athermal strengths of 14 alloying elements Al, C, Co, Cr, Cu, Mn, Mo, N, Nb, Ni, Si, Ti, V and W from the experimental data. Except for Al, Ni and Co, the athermal strengths of the common substitutional alloying elements are similar in magnitude, while the interstitial solutes C and N exert a stronger influence. Previously proposed superposition laws are used to account for the presence of multiple solutes having different athermal strengths. With an improved assessment of the magnetic parameters of alloy systems, the model predicts M_s temperatures within ±40 K for M_s > 300 K where thermal contributions to the frictional work can be neglected.     

Comment on the Article “Initial Reactions at the Electrodes of the FFC-Cambridge Process in Molten CaCl2 to Produce Ti” by P.S. Lai,M.L. Hu,Z.F. Qu,L.Z. Gao,C.G. Bai,T.X. Wang,S.F. Zhang,and G.B. Qiu

Metallurgical and Materials Transactions B -     

D.D.S.控制剪切机(续完)

三、D.D.S.电控系统 数字直流伺服(D.D.S.)系统是一个独立装置,它主要由程序控制系统、喂料系统和剪切系统等三部分组成,其方框图如下: 如图5所示,当机组具备自动剪切条件     

西德Hermann C.Starok公司H.A.H.N坐谈提要

一、钽粉的各种杂质对电容器漏电流寿命的影响二、氧的影响:氧含量不能太低,也不能太高,最好控制在1400—1700PPm 的范围中,因为在真空烧结过程中,外层的五氧化二钽熔化,而后与杂质碳发生反应,方程如下:5C+Ta_2O_5→2Ta+5Co↑这样就除去了部分杂质碳。     

用N.M.C.法分离钴和镍

用2-乙基-1-己基磷酸单2-乙基-1-己基脂(M2EHPA)从硫酸镍溶液中分离钴的方法进行了研究。M2EHPA的分离系数比D2EHPA大很多倍(D2EHPA是熟知的一种阳离子交换萃取剂)。 使用3级混合澄清装置,将含20％(体积)M2EHPA的有机试剂与含30克/升镍和12克/升钴的原始水溶液接触后,能获得这样的结果:萃余相含29.9克/升镍和0.002克/升钴,萃取相含0.14克/升镍和12克/升钴。将萃取相与含有CoSO_4的洗涤液混合,能有效地从有机相中除掉镍;与稀硫酸溶液接触很容易从有机相中反萃取出钴。在工业性设备中,是使用钴电解工序的废电解液作为反萃取液。使用N.M.C.法,反萃取液中的钴浓度被控制在100克/升左右。 根据本研究的结果,建立了一种分离钴和镍的方法。日本矿业公司利用这种方法,目前已能有效地分别生产出1300吨/年和3300吨/年高纯的钴和镍。     

C.C.C.轧机的工艺及结构特点

介绍了唐钢高速线材厂从美国birdsboro公司的紧凑式粗轧机的主要工艺参数和工艺、结构特点，提出了堆钢事故解决办法，展望了C．C．C．轧机的发展前景。     

A.M.T.Profil 84 型剖面自动测绘仪

瑞士测量技术公司制造的第二代A.M.J.Profil84型剖面自动测绘仪,可用于测量采场、峒室、隧道和其它地下开挖工程的剖面。其测定原理是以应用含一固定基线长度和一已测角度之三角函数的光电系统为基础。用一种旋转的镜筒在1～     

Titania S.P.A公司简介

KruppThissen集团占75％股份，ItalianIndustrialistAgarini占25％股份的德意合资企业人ST集团所属的TitaniaS．P．A公司，总公司和特鲁尼工厂在罗马北部，营销部在米兰。Titania公司有100名员工（其中包括驻米兰的国内和出口销售人员各5名），从生产到销售，以高质量、短交货期为经营方针，实现了钛的专业化生产。全体生产人员沿工艺流程从事全工序作业。在追求员工多能化的同时，努力提高质量。致力于除飞机之外的一般工业用纯钛的生产销售，开发新用途的愿望非常强烈。在特鲁尼的研究中心C．S．AT，进行机械性能试验，分析和研究…     

H.C.斯塔克集团概况

Ｈ．Ｃ．斯塔克集团为世界著名的难熔、硬质合金制品公司。本文对该公司的基本情况和发展现状作了简要介绍。     

仪器信息网(www.instrument.com.cn)简介

仪器信息网创办于1999年5月,是中国第一家科学仪器类专业门户网站,由中国分析测试协会和北京仪信网通科技有限公司共同建设,是中国分析测试协会、中国仪器仪表学会分析仪器学会唯一指定网站,运营宗旨为:"信息为王,技术为根,服务为本",开通以来受到业界各方人士的关注和欢迎,帮助买卖双方建立起了便捷的交流通道,并促进了相关单位的横向联系与合作,提高了仪器行业的信息化程度.