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通过化学分析预测锌基涂层耐蚀性能的专家系统

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冶金分析 2012年第4期32卷 1-5页

作者： BENGTSON Arne HILDEBRAND Lars swerea kimab ab 多特蒙德技术大学

本研究旨在开发一种用于预测锌基涂层耐腐蚀性的通用方法,其可以表示为加速盐雾试验中的总质量损失。本方法仅基于三个分析参数,即锌、铝和镁的总涂层质量。这种限制的原因是这三种参数可能通过在线分析获得。然后,预测的耐腐蚀性被包... 详细信息

本研究旨在开发一种用于预测锌基涂层耐腐蚀性的通用方法,其可以表示为加速盐雾试验中的总质量损失。本方法仅基于三个分析参数,即锌、铝和镁的总涂层质量。这种限制的原因是这三种参数可能通过在线分析获得。然后,预测的耐腐蚀性被包括在一个过程/质量控制系统。加速腐蚀试验在布雷斯特的swerea kimab IC(腐蚀研究所)以及比利时的冶金研究中心(CRM)进行。试验按照雷诺ECC1试验D172028/--C(12周)以及CRM研发的加速循环腐蚀试验进行。根据总质量损失情况,原材料被分为四个耐腐蚀级别。所有腐蚀试验都清晰、充分地说明了元素镁和铝的正面影响。对于涂层中大多数这些元素来说,元素镁和铝的影响比单独元素锌的影响大很多。因此,引入了一个新的量,叫做"等量元素锌涂层重量"。此量与锌、铝和镁的涂层重量线性相关。使用专家系统开发了一种用于预测耐腐蚀性的模型,此模型基于回归分析和"决策树"算法。根据上述提及的三个分析参数(即锌、铝和镁的总涂层质量),可以使用开发的模型准确对27种材料中的25种进行分类。总之,即使是在线状态,这种方法也有可能准确预测出腐蚀行为。出于材料研发的目的,还扩展了专家系统使其包括其他分析参数。

关键词：专家系统耐腐蚀性锌涂层辉光放电

激光诱导击穿光谱技术对冶金样品中钢及炉渣的同时分析

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冶金分析 2009年第2期29卷 8-13页

作者： BENGTSON Arne THOMAS Bjrk swerea kimab Drottning Kristinas vg 48

本研究的初衷是开发一种不均匀冶金样品中钢和炉渣的快速、同时分析方法,以用于工艺控制。该方法基于激光诱导击穿光谱技术(LIBS)。选择激光诱导击穿光谱技术是因为它既可以分析导电材料又可分析非导电材料,并且相对来说不易受样品形状... 详细信息

本研究的初衷是开发一种不均匀冶金样品中钢和炉渣的快速、同时分析方法,以用于工艺控制。该方法基于激光诱导击穿光谱技术(LIBS)。选择激光诱导击穿光谱技术是因为它既可以分析导电材料又可分析非导电材料,并且相对来说不易受样品形状及表面光洁度的影响。产生的不均匀样品包含大量亚毫米级的渣颗粒,这些颗粒在单次LIBS分析中不能从周围的钢里面分离出来。因此提出了一种方法来对样品表面进行行扫描,扫描以大约0.5mm的分辨率和10 mm的步长来进行。激光的脉冲速率为20 Hz,扫描速度为1 mm/s。炉渣颗粒在行扫描中表现为钢的"污染区",在这个区域中有高浓度的一些元素,如钙、铝及硅。基于单点校准,提出了一种数学模型来逐步评定所得出的数据。首先,辨别出"干净"的钢区域,测定出钢的成分;第二步,测定出扫描总长度范围内的平均成分;最后一步,通过差减法计算出炉渣的成分平均值。这种方法被应用于几个多相取样器采集的样品的分析。发现钢中的碳、硅、锰、磷、硫及铝等元素都可被测定,仅有百分之几的相对标准偏差。而在炉渣中,分析的相对标准偏差会更高,几个重要元素在10%左右。这一方法有望进一步被开发应用于更小的非金属夹杂物的快速分析。

关键词：激光烧蚀光学发射钢分析

Shear band formation in shaped rheocast aluminium component at various plunger velocities

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Transactions of Nonferrous Metals Society of China 2010年第9期20卷 1749-1755页

作者： M.BLADH M.WESSN A.K.DAHLE swerea SWECAST ab Materials and Manufacturing-Casting School of EngineeringJnkping University Materials Engineering The University of Qu eensland

Significant progress has been made in recent years in understanding and modelling the rheology of semi-solid *** models show the effects of the microstructure in terms of size and morphology of globules on the material *** recently it has been shown that semi-solid metals can behave as compacted granular materials such as sand.A particular signature of such deformation is that the deformation becomes concentrated into shear bands which are 10-20 grains *** bands have also been observed in a range of cast ***, it has been clearly shown that shear bands in high pressure die cast (HPDC) products are also the results of Reynolds *** bands are also known to be a common feature in semi-solid metal *** segregation banding in semi-solid metal (SSM) material and its dependence of plunger velocity were *** castings were made with the RHEOMETALTM process with a range of different plunger *** microstructural characteristics were investigated, with a particular emphasis on shear *** is shown that ingate velocities influence the location and characteristics of the shear bands.

关键词： rheocasting shear bands segregation Al-alloys RHEOMETAL^TM

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Low Porosity in Cast Magnesium Welds by Advanced Laser Twin-Spot Welding

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Materials Sciences and Applications 2019年第1期10卷 53-64页

作者： Karl Fahlstrom Jon Blackburn Leif Karlsson Lars-Erik Svensson swerea kimab KistaSweden University West TrollhattanSweden TWI Ltd. CambridgeUK

Porosity is reported to be a major issue when welding cast magnesium. Therefore, it is important to understand the pore formation mechanisms and find procedures that could be used to reduce porosity. This study investigated the possibility of using twin-spot optics for reducing the porosity in laser welded cast magnesium. Two twin-spot welding setups were compared using either a beam splitter or twin-spot welding with primary and secondary (placed in front of the primary optic) optics. The results showed that welding with a dual optic setup with a defocused secondary beam reduced the volumetric porosity in the weld to 5%. The highest levels of volumetric porosity were 30%, and were a result of using the dual optic setup, but with a defocused primary beam. No clear relation between the level of porosity and power or welding speed was found. It was found that the amount of porosity depended on the balance of the energy input (controlled by defocusing) between the two beams. Porosity formation can be reduced if the energy from the first beam results in the nucleation and initial growth of pores. Reheating by the second beam then allows the pores to grow and escape from the molten material without melting additional base material. Furthermore, twin-spot welding is shown to be a promising combination of a production friendly solution and high quality welding.

关键词： Laser Welding Cast Magnesium Twin-Spot Metallurgy Porosity Automotive AM50 Alloy

Prediction and Verification of Resistance Spot Welding Results of Ultra-High Strength Steels through FE Simulations

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Modeling and Numerical Simulation of Material Science 2015年第1期5卷 26-37页

作者： Oscar Andersson Arne Melander Department of Production Engineering KTH Royal Institute of Technology Stockholm Sweden swerea kimab Kista Sweden

Resistance spot welding (RSW) is the most common welding method in automotive engineering due to its low cost and high ability of automation. However, physical weldability testing is costly, time consuming and dependent of supplies of material and equipment. Finite Element (FE) simulations have been utilized to understand, verify and optimize manufacturing processes more efficiently. The present work aims to verify the capability of FE models for the RSW process by comparing simulation results to physical experiments for materials used in automotive production, with yield strengths from approximately 280 MPa to more than 1500 MPa. Previous research has mainly focused on lower strength materials. The physical weld results were assessed using destructive testing and an analysis of expulsion limits was also carried out. Extensive new determination of material data was carried out. The material data analysis was based on physical testing of material specimens, material simulation and comparison to data from literature. The study showed good agreement between simulations and physical testing. The mean absolute error of weld nugget size was 0.68 mm and the mean absolute error of expulsion limit was 1.10 kA.

关键词： Resistance Spot Welding FE Simulations High Strength Steel Material Modeling Weld Size

Life Cycle Assessment and Life Cycle Cost of Waste Management—Plastic Cable Waste

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Advances in Chemical Engineering and Science 2014年第2期4卷 221-232页

作者： Mats Zackrisson Christina Jonsson Elisabeth Olsson Energy and Environment Group Department of MaterialsSwerea IVF ABMolndalSweden

The main driver for recycling cable wastes is the high value of the conducting metal, while the plastic with its lower value is often neglected. New improved cable plastic recycling routes can provide both economic and environmental incentive to cable producers for moving up the “cable plastic waste ladder”. Cradle-to-gate life cycle assessment, LCA, of the waste management of the cable scrap is suggested and explained as a method to analyze the pros and cons of different cable scrap recycling options at hand. Economic and environmental data about different recycling processes and other relevant processes and materials are given. Cable producers can use this data and method to assess the way they deal with the cable plastic waste today and compare it with available alternatives and thus illuminate the improvement potential of recycling cable plastic waste both in an environmental and in an economic sense. The methodology applied consists of: cradle-to-gate LCA for waste material to a recycled material (recyclate);quantifying the climate impact for each step on the waste ladder for the specific waste material;the use of economic and climate impact data in parallel;climate impact presented as a span to portray the insecurities related to which material the waste will replace;and possibilities for do-it-yourself calculations. Potentially, the methodology can be useful also for other waste materials in the future.

关键词： Cable Recycling Life Cycle Assessment LCA Life Cycle Cost LCC Economic Analysis Climate Impact Waste Recycling

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钒微合金化钢的热影响区韧性

钢铁钒钛 2015年第3期36卷 104-110页

作者： Fahlstrm K Hutchinson B Komenda J Lindh-Ulmgren E Martin D Beladi H 师仲然王瑞珍 swerea kimab Box 7047 Kista Sweden SE- 16407 Institute for Frontier Materials Deakin University GeelongVictoria Australia 3217 不详

研究了结构钢单道次焊接接头,尤其是靠近融合线位置的粗晶热影响区(CGHAZ)的组织和力学性能。通常,这个区域的韧性比母材和焊缝金属的韧性要低很多,所以CGHAZ是最容易发生断裂的薄弱位置。重点关注钒微合金化钢板,并且与相同强度级别的... 详细信息

研究了结构钢单道次焊接接头,尤其是靠近融合线位置的粗晶热影响区(CGHAZ)的组织和力学性能。通常,这个区域的韧性比母材和焊缝金属的韧性要低很多,所以CGHAZ是最容易发生断裂的薄弱位置。重点关注钒微合金化钢板,并且与相同强度级别的铌微合金化钢板进行对比。为了充分利用钒的强化效果,有必要将氮含量提高至0.01%;为优化钢的性能,必须考虑钒与氮的配合。

关键词：钢钒焊接热影响区(HAZ) 韧性组织

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Microstructure of Plasma Sprayed Al2O3-3wt%TiO2 Coating Using Freeze Granulated Powder

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Journal of Materials Science and Chemical Engineering 2016年第7期4卷 8-14页

作者： Yiming Yao Ola Lyckfeldt Aurélien Tricoire Aurélien Tricoire Department of Materials and Manufacturing Technology Chalmers University of Technology Gothenburg Sweden swerea IVF ab Material Applications-Ceramics M?lndal Sweden GKN Aerospace Sweden ab Trollh?ttan Sweden

This study is aiming at controlling the microstructure of plasma sprayed Al2O3-TiO2 composite coatings using freeze granulated powders. As sprayed and sintered Al2O3 + 3wt%TiO2 powders were air plasma sprayed with industry process parameters and compared with a commercial powder. The resulting coatings were investigated with respect to powder flowability, porosity and microstructure of the granules. The results showed that microstructure and melting fraction in the coatings could be tailored with the freeze granulation process and heat treatment conditions.

关键词： Al2O3-TiO2 Freeze Granulation Plasma Spray Microstructure

Numerical Modelling of Continuous Casting as a Real Tool for Process Improvement

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Numerical Modelling of Continuous Casting as a Real Tool for...