冷轧镀锌板表面缺陷分析

采用宏、微观检验、扫描电镜观察和能谱分析等方法对冷轧和镀锌钢板表面缺陷进行分析。结果表明：夹层状和短细线状表面缺陷属于夹杂类缺陷,长细线状表面缺陷则源于板坯纵向裂纹。产生表面夹杂和裂纹缺陷的主要原因与钢液质量和连铸坯质量有关。     

Q235B钢热轧板带孔洞及边裂缺陷成因分析

采用宏观分析、化学成分分析、金相检验以及能谱分析等方法,对某钢铁公司生产的Q235B钢热轧板带中部孔洞和边裂缺陷的成因进行了分析。结果表明：该类热轧钢板的中部孔洞和边裂缺陷是由于连铸工艺出现异常,造成连铸板坯边部产生表层气孔以及中部产生较严重的硫偏析,从而使钢板中部生成了大量的条带状硫化物,特别是低熔点FeS的生成导致了中部孔洞缺陷的产生;而连铸板坯边部的表层气孔在轧制过程中导致了边裂缺陷的产生。     

冷轧带钢孔洞缺陷分析及对策

为防止冷轧板中产生孔洞缺陷,从轧制工艺因素考虑,必须选择合适的辊型.此外,还必须考虑材质因素,要对冷轧原材料中夹杂物的大小、形态和分布进行限制.     

HR-2合金锻棒心部孔洞形成原因

HR-2合金锻棒靠近心部位置存在尺寸较大的长条形孔洞。采用微观观察、能谱分析及有限元分析等方法对孔洞的产生原因进行分析。结果表明：在HR-2合金电渣重熔过程中出现了大尺寸的夹杂缺陷，且在墩粗过程中孔洞无法被焊合；未焊合的、长径比较大的初始孔洞沿拔长方向伸长，最终形成了长条形孔洞。     

热轧H型钢边部裂纹成因分析

通过对连铸坯进行宏观检验、化学成分分析以及金相检验等,对某钢厂型钢中型生产线生产过程中出现的批量热轧H型钢边裂缺陷产生原因进行了分析。结果表明:连铸坯存在内部裂纹缺陷以及非金属夹杂物含量较高,是导致该批H型钢产生边部裂纹的主要原因。最后针对缺陷成因提出了改进措施,使H型钢的边部裂纹情况得到了有效控制。     

连铸轴承钢质量的研究

采用宏观与显微分析方法对轴承钢连铸坯进行了剖析，揭示了连铸坯的氧、碳含量及各类夹杂的分布规律。结果表明，铸坯能满足高、低倍质量要求，中间包高液位和低温浇注有利于减少边缘夹杂。     

中厚钢板超声波探伤不合格原因分析

针对中厚钢板超声波探伤出现的两类典型缺陷,通过低倍检验和金相检验等手段,并结合实际探伤过程中缺陷的分布位置对探伤不合格的原因进行了分析。结果表明:点状密集型缺陷主要与连铸坯的中心偏析有关,侧边条型缺陷则主要来源于连铸坯的三角区裂纹或靠近三角区的中心裂纹,钢板体部的条型缺陷则是由连铸坯的中间裂纹造成的。     

冷轧汽车表面板常规夹杂缺陷分析

对冷轧汽车表面板常规夹杂缺陷的形貌特征以及形成原因进行了归纳总结。结果表明:冷轧汽车表面板常规夹杂缺陷主要以点状夹杂、边部翘皮、线状夹杂、条状起皮伴随白色条痕4种形貌出现,其中线状夹杂和条状起皮伴随白色条痕类夹杂是目前影响冷轧汽车表面板合格率最主要的缺陷;目前冷轧汽车表面板夹杂缺陷主要以Al2O3类夹杂为主,严重缺陷同时还存在保护渣类夹杂,主要在连铸工序中产生。     

大型连铸板坯延迟断裂原因分析

大型连铸板坯在库房放置时发生自然横向断裂.采用金相检验、扫描电镜观察和能谱分析等方法对断坯进行了分析.结果表明,浇注温度偏低,致使铸坯中存在大量的缩孔缺陷和收缩裂纹,最终导致连铸板坯发生延迟断裂.     

20~#钢管外折缺陷的原因分析及对策

针对某钢厂生产的20#钢管在穿孔过程中出现表面外折缺陷的质量问题,利用金相显微镜、扫描电镜及能谱仪对穿孔样品表面缺陷与连铸坯表面缺陷进行系统分析。通过对大量实验数据进行比较研究,得到表面缺陷的形态、分布及化学成分,并结合生产工艺分析外折缺陷产生的原因:连铸坯表面存在纵裂纹缺陷是导致穿孔管表面出现外折缺陷的主要原因。最后,结合该钢种的连铸生产工艺提出具体的改进建议。     

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