轮胎钢圈开裂失效分析

某公司生产的轮胎钢圈在安装服役15d左右后出现批量开裂现象,采用宏观分析、化学成分分析、力学性能测试、金相检验及断口分析等方法对轮胎钢圈的开裂原因进行了分析。结果表明:该批轮胎钢圈失效为早期疲劳开裂;轮胎钢圈轮辋侧焊缝熔合线处存在机加工刀痕,产生缺口应力集中,加之裂源处焊缝熔深不足降低了其疲劳性能,加速了疲劳裂纹的萌生和扩展,最终导致轮胎钢圈早期疲劳开裂。     

轮胎钢圈断裂分析

为了分析某轮胎钢圈的断裂性质和原因，本文对部分残骸进行了外观检查。对断裂钢圈断口进行了宏观和微观检查和分析，另外对断裂钢圈夹杂物进行了能谱分析。该断裂钢圈截面上夹层带的材质具有不均匀性；钢圈的疲劳断裂和扩展主要和大量氧化铁夹杂物有关。     

加氢装置中管道法兰密封钢圈的断裂分析

采用宏观及断口分析、金相与硬度检测、扫描电镜与能谱分析等方法,对加氢装置中管道法兰密封钢圈的断裂原因进行了分析。结果表明,断裂是由于管道中气体所含的H2S对钢圈内表面产生严重点蚀和钢圈组织不合理所致。当法兰螺栓紧固时,钢圈内表面所受的强大拉应力造成蚀坑底部的应力集中而形成裂纹源,而钢圈硬脆的淬火组织促进了裂纹在基体中的快速扩展,最终导致断裂。     

EXPLORATION OF A NEW APPROACH TO IMPROVE FATIGUE PROPERTY OF MATERIALSⅠ--An Increased Fatigue Life of Low Carbon Steel

研究了低碳钢经大电流脉冲处理后改善疲劳性能的可能性，结果表明：在循环载荷作用一定周次后，经大电流脉冲处理，可使低碳钢的疲劳性能得以改善，并可延长其疲劳寿命的量级。     

上海材料研究所招聘启事

1．金属材料疲劳性能检测：1人。要求：男，30-40岁；熟悉机械、材料相关知识，具有硕士学历或高级技术职称，有3年以上材料疲劳和断裂性能试验或研究工作经验，熟练使用各种材料疲劳试验机（低周、高频、旋转弯曲等），万能材料试验机等力学试验设备；熟悉材料的S-N曲线，P-S-N曲线，Kic，Ylc，da／dN，CTOD等疲劳和断裂性能的检测；熟悉相关的国内外检测方法标准。年薪：8-12万。     

疲劳状态检测元件的研究

疲劳状态检测元件对于检测在役的结构和构件的疲劳损伤状态具有独特的优势。对该元件的机理、工艺和性能进行了进一步的研究。采用四种箔材及两种制片工艺研制了疲劳状态检测元件，并对其性能进行了试验研究。实验结果表明，疲劳状态检测元件的阻值能够根据累积循环应变历程产生相应的变化。采用工艺1的疲劳状态检测元件的最大电阻变化率可达6．5％，而采用工艺2的最大电阻变化率为4．5％。研究结果表明，疲劳状态检测元件的制片工艺是影响其性能的主要原因。     

Uddeholm热疲劳图谱的分析与定量评定

通过建立热疲劳裂纹图像采集和计算机分析系统，对Uddeholm热疲劳评定标准图谱进行了分析，结果表明，Uddeholm标准图谱评定热疲劳程度是不够精确的，即无法用肉眼精确地评定热疲劳裂纹的级别，针对Uddeholm标准图谱的不足，提出损伤因子概念，并制作出一套相应的计算软件；用它定量地分析了进口8407S钢和国产4Cr5MoSiV1钢的热疲劳性能，揭示了两种钢的热疲劳性能的变化规律，实现了热疲劳裂纹的计算机辅助评定。     

硅酸铝短纤维增强ZL109复合材料的热疲劳性能

研究了用Ａｌ２Ｏ３溶胶或硅溶胶作粘结剂制备硅酸铝短纤维增强ＺＬ１０９复合材料的热疲劳性能，结果表明，仅用Ａｌ２Ｏ３溶胶粘结剂能制备的复合材料的热疲劳性能最好，仅用硅酸作粘剂制备复合材料的热疲劳性能最差，热疲劳裂纹不是沿纤维与基体之间的界面扩展，就是穿过纤维扩展，且与裂纹扩展方向和纤维的取向有关，随着热循环次数的增加，上述复合材料的硬度逐渐下降。     

氢蚀温度20G和15CrMo钢疲劳行为的影响

研究了氢蚀温度对２０Ｇ和１５ＣｒＭｏ钢常规力学性能疲劳性能和机制的影响以在力比对腐蚀后２０Ｇ钢疲劳性能的影响，结果表明，氢蚀后２０Ｇ钢的疲劳氢蚀对材料损伤程度和氢蚀导致和粗糙内裂纹途径造成产合效应增加两因素联合作用，氢蚀后１５ＣｒＭｏ钢脱碳严重，其疲劳行为仪受脱碳对材料的损伤作用的影响，应力比对２０Ｇ疲劳性能也有很大影响。     

腐蚀条件下高强钢超高周疲劳性能及损伤机理研究进展

在疲劳载荷作用下，材料发生裂纹萌生、扩展直至断裂的周次在107以上的过程被称为超高周疲劳。部分高强钢机械部件需在恶劣环境中服役，服役期间承受的疲劳载荷周次高达108～1011，高强钢在腐蚀环境中的超高周疲劳问题成为影响结构可靠性、安全性的关键问题，是航空航天、汽车、高铁等领域亟待解决的难点。得益于金属材料在传统疲劳问题上的总结积累与先进试验手段的助力，诸多学者开发出多种新的试验方法，有针对性地对高强钢在腐蚀条件下的超高周疲劳问题展开研究。目前，关于腐蚀条件下高强钢超高周疲劳性能退化规律及损伤机理、腐蚀条件下裂纹萌生竞争机制及裂纹初期扩展行为、氢对高强钢超高周疲劳性能及颗粒亮面形成机制的影响等核心问题的认识愈发清晰，逐渐从对试验现象的描述与归纳深入到对损伤机理的探索与推演，而且部分研究成果已经逐步在工程实践中得到应用。本文首先从S-N曲线等角度简述了高强钢无腐蚀条件下的超高周疲劳损伤特征;然后总结了典型腐蚀介质对高强钢超高周疲劳性能的影响，并指出氢脆断裂为高强钢在腐蚀环境中的断裂机理之一;随后详述了氢对高强钢超高周疲劳性能及颗粒亮面形成机制的影响研究进展;最后对几个关键问题进行了展望。     

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 ...     

Effect of Oxide Assisted Metal Nanoparticles on Microstructure and Morphology of Gallium oxide Nanowires

Several researches have been reported about the characteristic of β-Ga2O3 nanowires which was synthesized on nickel oxide particle. But indeed, recent researches about synthesis of β-Ga2O3 nanowires on oxide-assisted transition metal are limited to nickel or cobalt oxide catalyst. In this work, Gallium oxide (β-Ga2O3 ) nanowires were synthesized by a simple thermal evaporation method from gallium powder in the range of 700 - 1000℃ using the iron, nickel, copper, cobalt and zinc oxide as a catalyst, respectively. The β-Ga2O3 nanowires with single crystalline without defects were successfully synthesized at the reaction temperature of 850, 900 and 950℃ in all the catalysts. But optimum experimental condition in synthesis of nanowires varied with the kind of catalyst. As increasing synthesis temperature,the morphology of gallium oxide nanowires changed from nanowires to nanorods, and its diameter increased. From these results, we could be proposed that the growth mechanism of β-Ga2O3 nanowires was changed with synthesis temperature of nanowires. Microstructure and morphology of Synthesized nanowire was characterized by HR-TEM, FE-SEM, EDX and XRD.     

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