Fe-Mn-Si-Cr-Ni形状记忆合金超弹性的研究

用拉伸实验研究了Ｆｅ－１５．２Ｍｎ－６Ｓｉ－８．３Ｃｒ－７Ｎｉ、Ｆｅ－１６Ｍｎ－５Ｓｉ－９Ｃｒ－４Ｎｉ和３１７Ｌ不锈钢的应力应变曲线。结果表明,铁基形状记忆合金存在显著的超弹性。其应力应变曲线上,卸载时的曲线和再加载时的曲线相比有明显的滞后。合金卸载时存在极大的非线性回弹εｓｂ,εｓｂ随变形量的增加而增加,而超弹性应变εＳＥ在小变形量下随变形量的增加而增加,当总变形量超过一定值时,εＳＥ不再增加。Ｆｅ－１５．２Ｍｎ－６Ｓｉ－８．３Ｃｒ－７Ｎｉ的最大超弹性应变εＳＥ可达到０．７５％。应力诱发马氏体与母相之间界面移动产生超弹性,超弹性受化学驱劝力和母相对马氏体相的弹性约束控制。热形成马氏体和母相强度对超弹性影响不大。     

X射线衍射法测定Fe-Mn-Si形状记忆合金层错几率的研究

Ｆｅ－Ｍｎ－Ｓｉ合金的形状记忆效应来源于马氏体相变,而马氏体相变则通过奥氏体内形成每隔一层｛１１１｝面上的堆垛层错来完成。与层错能相关的层错几率可能控制马氏体的相变机制。本文根据Ｗａｒｅｎ的衍射理论,用Ｘ射线衍射峰位移和峰宽化两种方法测定了Ｆｅ－Ｍｎ－Ｓｉ合金的层错几率,其结果表明随锰含量增加,层错几率降低。本文着重对提高衍射峰位移和峰宽化两种测定方法的精度及其影响因素进行详细的研究,并认为峰位移法更简便     

Fe－Mn－Si－Ni－Co合金中形变应力诱发ε马氏体的稳定化及其对记忆效应的影响

Ｆｅ－２５．６Ｍｎ－５．１Ｓｉ－４．１Ｎｉ－１．８Ｃｏ（ｗｔ％）合金在一８０℃变形时，可逆应变量ε＿ｒ随预应变量ε＿ｔ增大而迅速增大；当ε＿ｔ＞２．５％，增大速度减慢；当４．２％＜ε＿ｔ＜１０．８％，ε＿ｒ基本保持恒定值。逆相变温度Ａ＿ｆ随ε＿ｔ增大而连续升高，但Ａ＿ｓ不随ε＿ｔ变化。应力诱发ε马氏体及其逆相变后的残留显微组织分析表明，应力诱发ε马氏体片在形成过程中因相互交叉产生塑性变形，引起稳定化，是引起多晶Ｆｅ－Ｍｎ－Ｓｉ系合金可逆应变量低的一个重要原因。文中还讨论了应力诱发ε马氏体稳定化的特点及可能的改善途径。     

Fe—Mn和Fe—Mn—Si粉末混合物的机械合金化

对Ｆｅ－２４Ｍｎ，Ｆｅ－２４Ｍｎ－６Ｓｉ成分的粉末混合物进行了机械球磨，并对不同时间的球磨样品进行了Ｘ射线衍射（ＸＲＤ）和Ｍｏ¨ｓｂａｕｅｒ谱测量。结果表明，球磨使得Ｆｅ、Ｍｎ、Ｓｉ在原子尺度上发生了混合，形成了顺磁性、面心立方结构的Ｆｅ－２４Ｍｎ或Ｆｅ－２４Ｍｎ－６Ｓｉ纳米晶合金，这是Ｆｅ、Ｍｎ或Ｓｉ原子由颗粒表面到体内扩散的结果。球磨６７ｈ以后结构未发生变化，表明形成的是一种热力学亚稳结构，这个结果与Ｆｅ－Ｍｎ和Ｆｅ－Ｍｎ－Ｓｉ合金在室温下的相图结构明显不同。     

预变形温度对Fe—Mn—Si—Ni—Cr合金形状记忆效应及γ←→ε转变的影响

研究了不同预变形温度下Ｆｅ－２５Ｍｎ－４Ｓｉ－２Ｎｉ－Ｃｒ合金的形状记忆效应和γ←→转变。结果表明，在２０３Ｋ进行预变形可以获得最大形状恢复率；适当降低预变形温度有利于应国诱发马氏体转变和形状忘儿应；但在７７Ｋ进行６％的预变形会使ε马氏体交割处产生全位错，不利于逆转变和形状记忆效应。     

含碳Fe—Mn—Si—Cr—Ni合金形状记忆效尖的研究

研究了碳加入后对Ｆｅ－１４Ｍｎ－５Ｓｉ－８Ｃｒ－４Ｎｉ合金形状记忆效应（ＳＭＥ）的影响。结果表明，碳元素的适当加入，有助于合金的可恢复应变的提高。在３．７５￣７．５％变形量时，含碳量为０．１２％的合金的可恢复应变量可达２．５￣３％，高于超低碳合金（Ｃ〈０．０２％）。     

Fe—Mn—Si形状记忆合金中元素对材料耐蚀性的影响

研究了Ｆｅ－Ｍｎ－Ｓｉ形状记忆合金中元素对材料耐腐蚀性能及形状记忆性能的影响。结果表明：在Ｆｅ－Ｍｎ－Ｓｉ合金中，随着Ｍｎ，Ｓｉ含量的增加，其耐腐蚀性能略有提高，但Ｍｎ含量过高会导致合金形状记忆性能下降。而在Ｆｅ－Ｍｎ－Ｓｉ合金中加入适量的Ｃｒ，可明显提高该合金的耐腐蚀性能，并使之具有良好的形状记忆性能。     

部分循环对FeMnSi基合金形状记忆效应的研究

用Ｘ射线衍射及热膨胀法研究了预应变量为３％的两种ＦｅＭｎＳｉ形状记忆合金在室温—４５０℃区间加热时形状恢复量及ε－马氏体量随温度的变化，结果表明ε马氏体在晶体中处于不同的能量状态，４５０℃加热后仍有部分应力诱发ε马氏体没有转变，这是该系列合金形状不能完全恢复的原因之一；同时发现，预应变后，合金中贮存弹性内应力，使得在Ａｓ～Ａｆ之间同一温度区间膨胀、收缩系数不同。     

Ni42Cr6Fe封接合金氧化膜和氧化物晶须的结构

用ＴＥＭ、Ｘ－Ｒａｙ、ＳＥＭ等技术研究了Ｎｉ４２Ｃｒ６Ｆｅ玻封合金在高温湿Ｈ２中形成的氧化膜及氧化物晶须的结构。结果表明：氧化膜主要由Ｃｒ２Ｏ３和（Ｆｅ，Ｍｎ）Ｃｒ２Ｏ４两组相成，氧化膜底层是以Ｃｒ２Ｏ３为主的组织，氧化膜表层是以（Ｆｅ，Ｍｎ）Ｃｒ２Ｏ４为主的组织；Ｓｉ在氧化膜与合金界面分布，Ａｌ则在内氧化层中形成内氧化物质点；氧化膜表面生长的氧化物晶须的杆部为（Ｆｅ，Ｍｎ）Ｃｒ２Ｏ４单晶，头部为     

Fe—17Mn—10Cr—5Si—4Ni合金低温应力诱发相变特点及其形状记？…

用Ｘ射线衍射分析、显微组织观察等研究了Ｆｅ－１７Ｍｎ－１０Ｃｒ－５Ｓｉ－４Ｎｉ合金在低温（低于室温）下应力诱发相变的特点及其形状记忆效应。合金在室温拉伸变形时,当应变量超过５％由于应力诱发ε马氏体的相变作用而形成的α′马氏体;当变形温度低于室温时应力优先诱发γ－α′马氏体转变。正是这种应力诱发相应特征的转变使合金的形状记忆效应在室温以下出现奇特低谷。     

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.     

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.     

新闻(英文)

正China and Greece Sign the Standardization Cooperation Agreement Witnessed by Chinese Premier Li Keqiang and Greek Prime Minister Antonis Samaras,AQSIQ Minister Zhi Shuping and ELOT Chairman and Executive Director Angelos Tolkas signed the SAC-ELOT Standardization Cooperation Agreement.The Agreement is one of the critical cooperation documents signed during Li Keqiang’s visit in Greece,encouraging China and Greece to