冷却-等温-冷却处理过程硼的晶界偏聚

用径迹显微照相技术研究了含硼 10× 10 - 6和 30× 10 - 6的 Fe- 40 % Ni合金在模拟冷却 -等温 -冷却处理过程后硼的晶界偏聚特征。结果表明 ,在从 115 0℃以 2℃ / s冷速分别冷却到 110 0℃ ,10 0 0℃ ,90 0℃ ,80 0℃和 70 0℃保温 2 min,然后再以 2℃ / s冷速冷却到 6 0 0℃水淬的冷却 -等温 -冷却过程中 ,硼在晶界会形成明显的偏聚 ,晶界偏聚量随等温温度的下降先有所减少后增加 ,最低值在 10 0 0℃左右出现。含硼 10× 10 - 6 合金在 80 0℃以上温度等温后冷到 6 0 0℃时 ,试样晶界偏聚包括连续硼偏聚带及一定量含硼析出相 ,其它试样沿晶硼偏聚带中硼主要以析出相形式存在。实验还观察到在晶内亚晶界上也有明显的硼偏聚存在 ,并在偏聚带两侧存在有贫硼区。在晶粒晶界与亚结构相交处 ,硼原子优先偏聚在晶粒晶界上     

耐热钢时效后韧度与强度变化的机理

采用冲击试验仪器化试验方法和拉伸试验方法对汽轮机缸体用耐热钢不同状态（未经时效、经过593℃时效5600h）的动态断裂韧度及抗拉强度和塑性进行了研究,同时进行了SEM和物相分析。结果表明,在不同试验温度条件下,与未时效相比,经时效后材料的KId值和断口的侧膨胀值均有所降低;抗拉强度稍有增加,塑性略有降低。在时效试样的晶内与晶界处碳化物数量略有增加,主要是含铬的M23C6相有微量从基体中弥散析出;部分碳化物颗粒发生聚集和长大,试样中第二相平均粒径相对稍大。     

700℃超超临界机组用617B镍基合金的组织结构和析出相

使用扫描电子显微镜(SEM)和透射电子显微镜(TEM)对比分析了617B镍基合金在750℃持久试样和时效态试样的组织结构和析出相。结果表明:在蠕变和时效过程中在晶内和晶界都析出复杂面心立方结构的M23C6,晶内析出有序立方结构γ′相,前者为多边形或条形,后者为粒状;随着试验时间的延长析出物的颗粒尺寸出现长大的趋势;应力对γ′相的生长影响不明显,但是对晶界碳化物有明显的影响;在长时间应力条件下,M23C6碳化物聚集长大。     

非等温回归再时效对7050铝合金组织与力学性能的影响

采用扫描电镜(SEM)、透射电镜(TEM)、硬度测试和拉伸测试研究了非等温回归再时效对7050合金组织和力学性能的影响。非等温回归处理的加热速率为5℃/min,回归终了温度包括160℃、190℃、220℃、260℃和300℃。结果表明:经120℃/24 h+RT■190℃+120℃/24 h的非等温回归再时效处理后,合金的力学性能最佳,其抗拉强度约为588 MPa,屈服强度约为558 MPa,延伸率约为23%,硬度值约为199HV。预时效态合金晶界平衡相η呈不连续分布,其尺寸约为49～70 nm,晶内析出相η'的平均尺寸约为5～6 nm;在190℃的非等温回归处理过程中,预时效态合金中的析出相发生了部分回溶,相的平均尺寸变小,其晶界相和晶内相的尺寸分别约为5～10 nm和3～6 nm,回归态合金晶界呈多列平行且无沉淀析出带(PFZ)不明显;再时效态合金的晶界相尺寸最大,约为91～108 nm,晶内相弥散,尺寸约为4～10 nm,无沉淀析出带变得明显,其宽度约为41 nm。     

加工硬化效应对Cu-3.2Ni-0.75Si合金时效组织和性能的影响

利用显微硬度法研究了Cu 3 .2Ni 0 .75Si合金不同时效组织的加工硬化效应对合金组织和性能的影响。研究表明 ,Cu 3 .2Ni 0 .75Si合金中Ni2 Si相的大小和分布对合金时效硬化效应产生显著的影响 ,4 5 0℃×8h时效组织加工硬化效应最大 ,变形量为 80 %时 ,显微硬度增幅在Hv60左右 ;5 5 0℃× 8h时效组织随变形量增加其硬度变化最平缓 ,变形量为 80 %时 ,显微硬度增幅仅为Hv1 0左右。随着变形量的增加 ,合金的导电率缓慢下降 ,80 %变形后 ,4 5 0℃× 4h、4 5 0℃× 8h和 5 0 0℃× 8h的时效组织导电率均下降 6%IACS左右 ,而5 5 0℃× 8h时效组织的导电率变化不大     

超硬铝LC9合金的超塑性研究

微细晶粒超硬铝LC9合金在470～530℃温度范围内,速率为8.33×10~(-4)～1.66×10~(-2)s~(-1)条件下拉伸呈显出良好的超塑性。在最佳超塑性条件下(T=515℃,ε=1.66×10~(-3)s~(-1))获得延伸率δ=1300％、流变应力δ=1.7MN/M~2应变速率敏感性指数m=0.66 金相和电镜观察表明,在超塑流变过程中,除发生晶界滑动,扩散蠕变外,还发生明显的动态再结晶以及晶内结晶学滑移,晶内位错密度随变形量增大而增加。扩散蠕变导致在横向晶界上形成新的条带区,出现晶界迁移和无沉淀区,同时存在晶内和晶界扩散。空洞在三角晶界处萌生,沿横向晶界方向的扩展连结,导致突然断裂。     

回归再时效中预时效温度对7050铝合金应力腐蚀性能的影响

采用硬度测试、电导率测试、慢应变速率拉伸、透射电镜和扫描电镜等方法,研究了回归再时效热处理工艺中预时效温度对7050铝合金微观组织和应力腐蚀性能的影响。结果表明:随着预时效温度升高,回归再时效后7050铝合金晶内析出相从以GP区为主转变为以η′相为主,晶界析出相逐渐粗化,晶界变得不连续分布,合金应力腐蚀敏感性降低;但晶界无沉淀析出带宽度增加,120℃时达到140nm,易导致应力集中和阳极溶解,合金抗应力腐蚀性能下降。预时效温度为80℃,即稍微欠时效时,7050铝合金抗应力腐蚀性能较好,在缓慢应变速率(10-6s-1)和3.5%NaCl溶液腐蚀介质下,合金抗拉强度为473.5MPa,伸长率为10.67%,应力腐蚀指数为0.05824。     

多级时效热处理对7056铝合金析出组织与耐蚀性的影响

利用透射电子显微镜(TEM)、扫描电子显微镜(SEM)、力学性能测试、电导率测试以及剥落腐蚀、慢应变速率拉伸应力腐蚀(SSRT)、Tafel循环极化曲线等手段研究多级时效热处理对7056铝合金析出组织及耐蚀性的影响。结果表明:过时效再时效热处理后溶质原子二次析出,晶内析出相体积分数增大,晶界析出相粗化断开,无沉淀析出带宽化。与120℃/24h相比,采用120℃/6h预时效工艺有利于晶内细小析出相回溶和粗大相长大。再时效热处理可提高过时效合金的强度和电导率,与峰时效和回归再时效相比,合金的抗拉强度损失不大,电导率明显提升。过时效再时效热处理后,合金晶界处连续阳极溶解被有效避免,抗剥落腐蚀和抗应力腐蚀性能增强。     

时效制度对挤压+锻造工艺路线FGH95粉末高温合金组织和性能的影响

采用不同的时效制度处理热等静压+挤压+等温锻造工艺的FGH95合金,并对处理后合金的显微组织和力学性能进行了系统研究。结果表明,经过双级时效(870℃/1 h,AC+650℃/24 h,AC)和单级时效(760℃/10 h,AC)处理后,合金的晶粒度无明显差异,但γ′相的数量、尺寸及分布存在显著差异。相比于单级时效,双级时效可以更有效地促进晶内γ′相粗化,晶内γ′相平均直径达到78 nm,而单级时效为67 nm;同时,双级时效更有利于M 3B 2等晶间强化相的析出。二者的拉伸强度水平相当,但双级时效合金的持久寿命低于单级时效合金,而其持久塑性要优于单级时效合金。     

长期运行X20CrMoV12.1钢管材的性能劣化及其表征

对上海某电厂X20CrMoV12.1钢主蒸汽管道经16×104h运行后的力学性能及其显微组织进行了表征和评价.试验结果表明,管材的冲击性能下降明显,常温下呈脆性状态.试样的断口分析和显微结构表征进一步显示管材组织劣化显著、蠕变损伤特征明显、晶界碳化物球化严重以及晶内粗大的碳化物沉淀生成.     

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