W6Mo5Cr4V2钢形变热处理组织的电镜分析

利用透射电子显微技术研究了Ｗ６Ｍｏ５Ｃｒ４Ｖ２钢在７５０－１１５０℃温度范围内等温形变０－６５％后直接淬火或２７０℃等温淬火的显微组织。结果表明：形变诱发了ＭＣ型碳化物，且析出碳化物的分布和形态与形变参数有关；ＭＣ与母相奥氏体的取向为三基矢分别平行，且ＭＣ的析出不影响随后相变产物的形貌；马氏体和贝氏体铁素体的惯习面为〔１１１〕γ，它们与奥氏体、ＭＣ间有这样的关系：〔１１１〕ＭＣ／／（１１１）γ／／     

7Cr2WMoVSi钢热处理过程的碳化物的变化

本文研究了７Ｃｒ２ＷＭｏＶＳｉ钢热处理过程的碳化物的变化，结果表明，随退火温度降低，碳化物尺寸减小，７８０～８００℃退火获得均匀细化的球化组织；加热至９４０～９８０℃奥氏体化时，Ｍ３Ｃ，Ｍ２３Ｃ６已全部溶解，仍存在Ｍ６Ｃ和较多的ＶＣ剩余碳化物，有效地阻碍了奥氏体晶粒长大，随回火温度升高，按Ｍ３Ｃ，Ｍ２３Ｃ６，Ｍ６Ｃ，ＶＣ依次沉淀析出，各类碳化物的不同析出过程，提高了钢的回火抗力。     

30CrMnSiA钢的回火组织转变

对三种含砷量的３０ＣｒＭｎＳｉＡ钢进行了不同温度的回火处理，在室温下测取了回火处理试样的穆斯堡尔谱，同时对典型试样作了金相和俄歇电子能谱（ＡＥＳ）分析。试验结果表明。３０ＣｒＭｎＳｉＡ钢经淬火十回火处理后，其室温组织为α＇固溶体、碳化物和少量残余奥氏体的混合组织。回火温度不同，碳化物的形态也不一样，残余奥氏体含量随回火温度升高而降低。低温回火脆性主要是残余奥氏体分解与ε＋θ碳化物析出综合作用的结果。     

Nd0.67(Sr,Ca)0.33Mn(O,F)3磁电阻材料的结构与性能

通过掺ＣａＦ２制得了Ｎｄ０．６７（Ｓｒ,Ｃａ）０．３３Ｍｎ（Ｏ,Ｆ）３（ＮＳＭＯ）磁电阻材料,并对它们作了结构分析和磁性能测量。Ｘ射线衍射结果表明,ＮＳＭＯ化合物保持Ｎｄ０．６７Ｓｒ０．３３ＭｎＯ３的钙钛矿结构,空间群为Ｐｂｎｍ,Ｚ＝４,Ｆ＾离子占据８ｄ位置,随着ＣａＦ２掺和量的增加,晶格常数减小,居里温度降低,而磁电阻性质呈明显的递增趋势。     

高温正火消除85Cr2Mn2Mo钢组织遗传的研究

在研究８５Ｃｒ２Ｍｎ２Ｍｏ钢的组织遗传的基础上,着重研究了该钢组织遗传的消除,采用高温正火工艺,使８５Ｃｒ２Ｍｎ２Ｍｏ钢经重结晶,奥氏体再结晶有效地细化了奥氏体晶粒,切断了组织遗传,并对８５Ｃｒ２Ｍｎ２Ｍｏ钢的奥氏体再结晶温度做了有益的探析。     

热轧双相钢回火后的显微组织研究

研究了热轧以相钢Ｆｅ－０．０７８Ｃ－１．４４Ｍｎ－１．１１Ｓｉ－０．３８Ｃｒ经不同温度回火后的显微组织变化。透射电镜观察表明：热轧双相钢的组织中不可避免地混有少量珠光林（＜５％），它们对钢的基本力学性能并没有多大影响。本钢种２００℃回火组织中，马氏体基本不变化，为板条态，双相钢仍保持屈服行为；３００℃回火组织中，大量马氏体发生分解，形成碳化物，与少量珠光体交界处的马氏体首先发生分解。该温度回火完全     

超高强度钢连续冷却组织和时效反应的研究EI

观察分析了冷却速度对低合金超高强度钢（４０ＣｒＭｎＳｉＭｏＶＡ）精细组织的影响。结果表明，在冷却、低温等温（或回火）过程中，钢显微组织中的马氏体或贝氏体存在时效阶段。其组织特征为呢纹花样。α和ε间的取向不满足Ｊａｃｋ关系，它属一种新的取向关系。过渡型碳化物可直接从呢纹花样区析出。     

影响GCr15钢M／B复相组织强韧性的主次因素初探

通过正交设计试验和方差分析方法讨论了奥氏体化温度，形成贝氏体的等温温度及贝氏体的相对量对ＧＣｒ１５钢Ｍ／Ｂ复相组织的冲击韧性与硬度的影响。结果表明：贝氏体的相对量显著影响复相组织的冲击韧性及硬度，而奥氏体化温度和开成贝氏体的等温温度则对其影响不大。     

30CrMnSiA和30CrMnSiNi2A钢超高温淬火组织与性能的研究

研究了３０ＣｒＭｎＳｉＡ、３０ＣｒＭｎＳｉＮｉ２Ａ钢超高温淬火组织与力学性能关系。试验结果表明，在该钢Ａｃ３以上－２００℃超高温淬火可获得组织细小均匀的板条马氏体加残余奥氏体。控制超高温淬火加热保温时间，毁唯奥氏体化又能获得细小奥氏体晶粒，从而显著提高了该钢的强韧性。     

7Cr7Mo3V2Si钢加热相变研究

利用Ｆｏｒｍａｓｔｏｒ全自动相变测定仪研究了７Ｃｒ７Ｍｏ３Ｖ２Ｓｉ钢在连续加热条件下的相变规律及特点；测定了能反映其相变规律与特点的奥氏体形成图。结果表明，钢中球状珠光体向奥氏体的转变是在较宽的温度区间（Ａｃ１ｂ－Ａｃ１ｅ）内完成的；钢中大量合金碳化物的溶解、按其难易程度不同分别与ｎ个溶解温度相对应；连续加热条件下，奥氏体难以实现均匀化。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...     

Brainstorming for ISO Strategy 2016-2020

正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from     

CNAS Passes APLAC's PTP Review

正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively.