杯壶用大口径薄壁钛焊管性能研究

针对Φ102 mm×0.5 mm×380 mm的大口径薄壁Gr.1钛焊管,选取不同的退火制度对钛焊管进行热处理,对比分析钛焊管的力学性能、工艺性能和不同位置的组织和硬度.研究发现:选择合适的热处理制度可有效提高大口径薄壁钛焊管焊缝位置的伸长率,明显降低热影响区、焊缝、母材的硬度差;当再次加工变形率达到35%的时候,焊缝中的锯齿状组织转变为等轴状组织.     

如何选择换热器管——选用焊管还是无缝管？

关于换热器选用无缝管还是焊管的争论，一般围绕在管材的结构完整性、焊缝与非焊缝的耐腐蚀性、服务工况的苛刻程度、非破坏性试验（NDE）以及验收要求和交货时间上。本文从实践性角度阐述了换热器管的生产过程、耐腐蚀性及焊管与无缝管机械完整性方面的内容。同时，也从最终用户的角度，从非破坏性试验（NDE）要求、耐腐蚀性评估和故障后果等方面论述了在某一特定应用下，如何确定使用何种换热器管是最合适的。     

TA19双态组织钛合金线性摩擦焊接头的组织结构及演化行为

本实验研究了具有双态组织结构特征的TA19钛合金线性摩擦焊接头的组织结构,分析了等轴初生α相和片层结构β转变组织的变形行为及接头焊缝的形成机制。结果表明:线性摩擦焊接时剧烈的连续热塑性变形使得焊缝中心的TA19双态组织钛合金经历了组织粗化、变形、破碎以及完全碎化的过程,最终转变为超细晶等轴组织。从焊接接头的热影响区到焊缝中心,等轴初生α相经历了不连续的塑性变形和破碎最终完全相变为β相。片层结构β转变组织则先后经历了变形、解体并完全碎化的过程。     

工艺参数对MIG焊铝铜合金焊缝组织的影响

研究了电磁搅拌工艺参数对2219铝铜合金脉冲MIG焊焊缝形状和组织的影响．结果表明,随着磁感应强度增加,焊缝枝晶数量减少,等轴晶数量增加,焊缝由指状熔深变为成形良好的椭圆形熔深．当磁感应强度和频率匹配合适时,焊缝成形良好,焊缝组织几乎为细小的等轴晶．但随着磁感应强度继续增加,焊缝成形变差,焊缝等轴晶数量减少,枝晶数量增多．电磁搅拌频率对焊缝成形影响不大,频率较低和较高时都会降低焊缝组织的细化效果．     

发动机用K439B镍基高温合金光纤激光自熔焊性能分析

采用激光自熔焊方法连接K439B焊接头,开展焊接头组织结构转变并对其力学特性进行了测试,分析焊接速率对其焊缝微观组织及焊缝变形程度的影响。研究结果表明:随着焊接速率提高,K439B焊接头获得热输入低,靠近焊缝中心部以等轴晶为主柱状晶,基本都是出现在熔合线区域,形成更细的焊缝组织,并引起焊缝硬度的明显提升。随着焊接速率增加,K439B焊接头拉伸强度和伸长率均表现出先增加后减小,最大值发生在焊接速率4 m/min时,此时拉伸强度和伸长率分别为852 MPa和44.5%。对焊接速率4 m/min下K439B焊接头在焊缝内形成了连续分布的胞晶、柱状晶、等轴晶。K439B焊接头形成了平整的表面区域,存在许多韧窝结构,主要表现为穿晶断裂的特点,焊缝端部发生了明显变形。     

钛及钛合金ECAP变形研究进展

综述了等径变曲通道变形(Equal channel angular pressing,ECAP)技术制备超细晶(Ultra fine grain,UFG)钛及钛合金的研究进展。总结了模具参数、变形工艺参数对钛及钛合金ECAP变形及组织的影响,以期通过制定合理的变形工艺制备出组织均匀、性能优良的超细晶钛及钛合金,同时汇总了钛及钛合金ECAP变形组织变形机理、演变机理、ECAP变形组织稳定性及超细晶材料性能(超塑性、疲劳强度、耐腐蚀性等)的研究进展,最后指出ECAP制备超细晶钛及钛合金的研究方向。     

冷拉变形及退火对新型70Cu-1Sn黄铜组织和性能的影响

本文研究了不同冷拉变形量和退火处理对新型70Cu-1Sn黄铜显微组织和性能的影响。结果表明:在铜锌二元合金中加入少量Sn、Al、P、Ni合金元素构成了新型的70Cu-1Sn合金,合金元素以固溶体的形式存在于晶粒内部,合金为α单相组织。随着冷拉拔变形量增大,沿着冷拉拔方向晶粒的变形程度逐渐增大,当变形量达43%时出现片状纤维组织;衍射峰宽化程度逐渐增大,没有发生相变或者有序化转变。加工硬化过程中合金的硬度、抗拉强度、脱锌腐蚀深度和腐蚀电流密度快速增加,但其伸长率、腐蚀电位逐渐降低,导致合金耐腐蚀性逐渐变差。退火态的合金以等轴晶为主,晶粒内部有一定数量的退火孪晶,其脱锌腐蚀深度约为17μm,其脱锌腐蚀深度远小于加工率43%的合金的155μm,其腐蚀电位最高且电流密度最小。     

TA19/TB2异质钛合金线性摩擦焊试验研究

目的 探究TA+TB钛合金组合的线性摩擦焊（LFW）接头组织及力学性能特点。方法 进行了TA19/TB2异质接头LFW焊接试验。利用光学显微镜及扫描电镜观察分析了接头微观组织特征,利用拉伸试验机及显微硬度计测试分析了接头力学性能。结果 TA19侧焊缝区为动态再结晶形成的等轴细晶组织,晶内析出了针状α''及细小片层α,热力影响区晶粒发生了不同程度的变形,在近焊缝较宽范围内形成水平流线形貌;接头中部界面TA19侧形成了直径约为2~3 μm的细小等轴晶;TB2侧焊缝区由动态再结晶形成的等轴晶及部分变形晶粒组成,热力影响区晶粒变形程度较低未形成流线形貌。接头界面两侧组织特征具有不同程度的强化效果,TA19侧从母材区到界面显微硬度值逐渐增大,TB2侧焊缝及热力影响区显微硬度值略高于母材;接头拉伸强度与TB2母材相当。结论 说明TA19与TB2钛合金可通过LFW获得可靠连接。     

复合SPD制备超细晶6061铝合金的组织及性能

采用反复镦压和等径角挤压相结合的复合挤压技术,在室温对退火态的6061铝合金进行4道次变形,获得等轴的超细晶铝合金。借助于透射电镜对变形过程的微观组织演变过程进行观察,提出了复合挤压过程中晶粒细化的过程。对不同实验状态的试样进行了硬度和拉伸实验,试样三个垂直面的硬度值增加了1倍,抗拉强度由165 MPa增加到402.7 MPa,但伸长率由26.8%下降到9.7%,复合挤压比等径角挤压对试样的力学性能影响更剧烈。     

超细晶纯钛疲劳裂纹的扩展行为

对纯钛进行2道次室温等径弯曲通道变形(ECAP)、等径弯曲通道变形加旋锻复合变形(ECAP+RS)并在旋锻后在300℃和400℃退火1 h,制备出4种具有不同组织的超细晶纯钛。对这4种超细晶纯钛进行疲劳裂纹扩展实验并观察分析超细晶纯钛的显微组织和疲劳断口的形貌,研究了裂纹的扩展行为。结果表明：显微组织对超细晶纯钛的疲劳裂纹扩展门槛值和近门槛区有显著的影响;超细晶纯钛的疲劳裂纹扩展门槛值随着塑性变形量的增大而增大,随着旋锻后退火温度的提高而降低;疲劳裂纹扩展速率曲线因超细晶纯钛晶粒尺寸和强度的影响出现转折,转折前ECAP+RS复合变形纯钛的抗疲劳裂纹扩展能力比ECAP变形强,且随着退火温度的提高而降低;转折后4种超细晶纯钛的疲劳裂纹扩展速率相差较小,呈现出相反的结果。疲劳裂纹扩展寿命中转折前近门槛区裂纹扩展寿命占绝大部分,因而转折前的门槛值与近门槛区的扩展速率对抗裂纹扩展能力更为重要。     

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