Practical Metallography最新文献_第9页

Meeting Diary 会议的日记

Practical Metallography Pub Date : 2023-01-30 DOI: 10.1515/pm-2023-0012

引用次数: 0

The effect of shielding gas on weldability of the AISI 420 martensitic stainless steel 保护气体对AISI 420马氏体不锈钢可焊性的影响

Practical Metallography Pub Date : 2023-01-30 DOI: 10.1515/pm-2021-1000

İ. Acar, B. Çevik, B. Gülenç

{"title":"The effect of shielding gas on weldability of the AISI 420 martensitic stainless steel","authors":"İ. Acar, B. Çevik, B. Gülenç","doi":"10.1515/pm-2021-1000","DOIUrl":"https://doi.org/10.1515/pm-2021-1000","url":null,"abstract":"Abstract Most of weld defects occurring in the welding of martensitic stainless steels are caused by the presence of hydrogen. Thus, the effects of hydrogen in the weld zone need to be well-understood to estimate the quality and service life of martensitic stainless steel joints. In the present study, AISI 420 martensitic stainless steel materials were welded by using different combinations of shielding gas via the gas metal arc welding (GMAW) method. It is known that shielding gases also play a critical role in heat input, cooling rate, microstructure of weld seam, weld defects, and mechanical properties besides drying of molten weld pool. Thus, it is important to investigate the effects of shielding gases and gas combinations on the welding of martensitic stainless steels in the welding process. In the present study, 100 % Ar, 97 % Ar + 3 % H2 and 93 % Ar + 7 % H2 gas combinations were employed. The welded sheets were subjected to the metallographic examination as well as hardness, tensile, and bending tests. The effect of the tests and the combination of shielding gas on the mechanical and microstructural properties of AISI 420 stainless steel was investigated. The results indicated that a noticeable grain coarsening occurred in the microstructure of the weld metal and heat affected zones (HAZs) after the addition of H2 into the Ar gas during the welding process. The highest tensile strength was obtained from the joints with 100 % Ar gas. As a result of the tensile test, rupture occurred in the base metal-HAZ transition zone in all the welded samples. In the joints welded with 97 % Ar + 3 % H2 and 93 % Ar + 7 % H2 gas combinations, fracture occurred in the base metal-HAZ transition zone during the bending test.","PeriodicalId":20360,"journal":{"name":"Practical Metallography","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79562448","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Classification of fracture characteristics and fracture mechanisms using deep learning and topography data 基于深度学习和地形数据的裂缝特征和断裂机制分类

Practical Metallography Pub Date : 2023-01-30 DOI: 10.1515/pm-2022-1008

L. Schmies, B. Botsch, Q. Le, A. Yarysh, U. Sonntag, M. Hemmleb, D. Bettge

{"title":"Classification of fracture characteristics and fracture mechanisms using deep learning and topography data","authors":"L. Schmies, B. Botsch, Q. Le, A. Yarysh, U. Sonntag, M. Hemmleb, D. Bettge","doi":"10.1515/pm-2022-1008","DOIUrl":"https://doi.org/10.1515/pm-2022-1008","url":null,"abstract":"Abstract In failure analysis, micro-fractographic analysis of fracture surfaces is usually performed based on practical knowledge which is gained from available studies, own comparative tests, from the literature, as well as online databases. Based on comparisons with already existing images, fracture mechanisms are determined qualitatively. These images are mostly two-dimensional and obtained by light optical and scanning electron imaging techniques. So far, quantitative assessments have been limited to macroscopically determined percentages of fracture types or to the manual measurement of fatigue striations, for example. Recently, more and more approaches relying on computer algorithms have been taken, with algorithms capable of finding and classifying differently structured fracture characteristics. For the Industrial Collective Research (Industrielle Gemeinschaftsforschung, IGF) project “iFrakto” presented in this paper, electron-optical images are obtained, from which topographic information is calculated. This topographic information is analyzed together with the conventional 2D images. Analytical algorithms and deep learning are used to analyze and evaluate fracture characteristics and are linked to information from a fractography database. The most important aim is to provide software aiding in the application of fractography for failure analysis. This paper will present some first results of the project.","PeriodicalId":20360,"journal":{"name":"Practical Metallography","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87851987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Combination of Digital Image Correlation (DIC) and in situ 3D-μ-CT in the analysis of the relationship between strains and porosity under creep loading 结合数字图像相关(DIC)和原位三维μ- ct分析蠕变载荷下应变与孔隙率的关系

Practical Metallography Pub Date : 2023-01-30 DOI: 10.1515/pm-2023-0008

B. Camin, J. Hornig-Klamroth, N. zu Bentheim

引用次数: 0

Imperfections in Inner Cavity of Row 4 Turbine Blade Caused by Metal-Core Reaction 第四排涡轮叶片金属芯反应引起的内腔缺陷

Practical Metallography Pub Date : 2023-01-30 DOI: 10.1515/pm-2023-0009

A. Neidel, E. Cagliyan, B. Fischer

{"title":"Imperfections in Inner Cavity of Row 4 Turbine Blade Caused by Metal-Core Reaction","authors":"A. Neidel, E. Cagliyan, B. Fischer","doi":"10.1515/pm-2023-0009","DOIUrl":"https://doi.org/10.1515/pm-2023-0009","url":null,"abstract":"Abstract When selecting case studies for presentation in this section Failure Analysis of Practical Metallography, the authors of this contribution asked themselves time and again what conditions actually constitute a component failure. Conventional wisdom has it that a failure occurred when a component or assembly lost its function intended by design. The authors readily admit that this is decidedly not the case for the “failure” presented in this contribution. Not only did no failure occur (the component was successfully used in engine service for the intended operating time), but the subject turbine blade did not loose its intended function by any stretch of the imagination. Why is this case study then presented here anyway? Because the evaluation and assessment of severity of indications found upon non-de structive testing of the subject turbine blade was only possible after destructive metallurgical investigation. One could jokingly concede that the blade definitely lost its function after metallographic cut-up. In any case, in the “failure case” presented in this contribution, the engineering department did not dare to release the subject turbine component for renewed engine service after refurbishment, since indications were detected that could not be properly assessed, without destroying the part; hence the subject component was not fit for engine service. The inclined reader may himself decide whether this fact makes it a component failure.","PeriodicalId":20360,"journal":{"name":"Practical Metallography","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84618885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Visualization of magnetization reversal processes by dynamic Kerr microscopy 动态克尔显微镜下磁化反转过程的可视化

Practical Metallography Pub Date : 2022-12-18 DOI: 10.1515/pm-2023-0002

D. Hohs, S. Klett, R. Löffler, F. Trier, D. Goll, G. Schneider

引用次数: 0

Determination of grain size distribution of prior austenite grains through a combination of a modified contrasting method and machine learning 通过改进的对比方法和机器学习相结合的方法确定先验奥氏体晶粒的粒度分布

Practical Metallography Pub Date : 2022-12-18 DOI: 10.1515/pm-2022-1025

M. Laub, Björn Bachmann, E. Detemple, F. Scherff, T. Staudt, M. Müller, D. Britz, F. Mücklich, C. Motz

{"title":"Determination of grain size distribution of prior austenite grains through a combination of a modified contrasting method and machine learning","authors":"M. Laub, Björn Bachmann, E. Detemple, F. Scherff, T. Staudt, M. Müller, D. Britz, F. Mücklich, C. Motz","doi":"10.1515/pm-2022-1025","DOIUrl":"https://doi.org/10.1515/pm-2022-1025","url":null,"abstract":"Abstract The prior austenite grain size (PAGS) represents one of the most significant microstructural parameters for steel research and process development. Since the PAGS directly correlates with recrystallisation during rolling in the manufacturing process of steel plates, it has a huge influence on its mechanical properties. Methods to determine the PAGS reliably and reproducibly are in high demand. There are several different approaches, based on different working principles, aiming to measure the PAGS. In this paper, the focus will be held on chemical etching methods because they allow, other than indirect techniques, space-resolved images as output, coupled with a fast application with good statistics and do not necessarily require a pretreatment of the specimen that can alter properties of interest. A parameter study has been conducted to identify unknown influencing variables as well as to tune well known parameters for their application to low-carbon steels. In the scope of this work, a novel and objective way of determining the PAGS is being presented. A reproducible approach has been developed that is able to automatically reconstruct the prior austenite grain boundaries (PAGB) from low-carbon steels and thereby determining the PAGS. Based on an improved etching recipe, a routine could be elaborated using modern methods of machine learning in the field of computer vision that is able to quantitatively analyze optical micrographs. Semantic segmentation is used to detect the PAGB based on correlative EBSD data and expert’s annotations; thus, reconstructing the prior morphological microstructure. Therefore, besides the determination of the average grain size, the distribution of the PAGS and their morphological parameters can be quantified.","PeriodicalId":20360,"journal":{"name":"Practical Metallography","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87649704","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Ferrite in the HAZ of Dissimilar Temperature Probe Welds 不同温度探头焊缝热影响区内的铁素体

Practical Metallography Pub Date : 2022-12-18 DOI: 10.1515/pm-2023-0003

A. Neidel, M. Giller, S. Riesenbeck

引用次数: 0

Materialographic sample preparation of ancient copper materials 古铜质材料的材料学样品制备

Practical Metallography Pub Date : 2022-11-27 DOI: 10.1515/pm-2022-0071

H. Cloeren

引用次数: 0

Metallography on a sickle fragment from the Drassburg/Burgenland hoard find 德拉斯堡/布尔根兰窖藏发现的镰刀碎片的金相分析

Practical Metallography Pub Date : 2022-11-27 DOI: 10.1515/pm-2022-1005

R. Haubner, S. Strobl

引用次数: 0