Practical Metallography最新文献

Less is sometimes more – some examples of the reduction of hazardous substances in metallographic etching 少有时就是多--减少金属蚀刻中有害物质的一些实例

Practical Metallography Pub Date : 2024-07-01 DOI: 10.1515/pm-2024-0038

H. Schnarr

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Do cracked jaws of the four-jaw chuck of a large lathe pose a danger? 大型车床四爪卡盘的卡爪破裂会造成危险吗？

Practical Metallography Pub Date : 2024-07-01 DOI: 10.1515/pm-2024-0048

J. Rockel, E. Cagliyan, B. Fischer, A. Neidel

{"title":"Do cracked jaws of the four-jaw chuck of a large lathe pose a danger?","authors":"J. Rockel, E. Cagliyan, B. Fischer, A. Neidel","doi":"10.1515/pm-2024-0048","DOIUrl":"https://doi.org/10.1515/pm-2024-0048","url":null,"abstract":"\u0000 All the jaws of a four-jaw chuck mounted on the faceplate of a large lathe were received by the material testing laboratory to undergo metallurgical failure analysis. Each of the four jaws exhibited cracks in the fillet radius between one of the gripping surfaces and the long horizontal part. The cracks were just visible to the unaided eye und had been discovered by an alert mechanic. One of the jaws was selected for further material analysis for which the crack was opened to undergo fractographic evaluation. The analysis also involved the evaluation of the material using optical emission spectrometry, the preparation of a metallographic sample, and hardness testing. The cracks occurred as a result of repeated overload at the crack initiation sites located in the fillet radius. This was not a single overload event which would not have caused the jaws to crack, but a series of overload events. The situation did not pose a safety hazard to the staff since the soft and tough core of the case-hardened jaws would have retarded, if not stopped, crack growth. A sudden disastrous failure of the jaws by breaking off, for example, and extremely heavy components crashing down as a result were not an imminent threat. This dangerous failure scenario would have been enabled if the jaws had been through-hardened. Instead, casehardening heat treatment had been applied which is the correct choice for this type of component.","PeriodicalId":508095,"journal":{"name":"Practical Metallography","volume":"108 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141842306","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}

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What if fractography does not tell us anything? – Failure of a side seal retainer 如果碎裂图什么都显示不出来怎么办？- 侧密封固定器失效

Practical Metallography Pub Date : 2024-07-01 DOI: 10.1515/pm-2024-0047

B. Fischer, M. Giller, E. Cagliyan, A. Neidel

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Interview with Dr. Volker Hinrichs 采访沃尔克-欣里希斯博士

Practical Metallography Pub Date : 2024-07-01 DOI: 10.1515/pm-2024-0051

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Collaborative experiment of the work group “Sample Preparation” on the subject “Reduction of hazardous substances in metallographic etching using electrolytic etching techniques” 样品制备 "工作组就 "利用电解蚀刻技术减少金相蚀刻中的有害物质 "这一主题开展合作实验

Practical Metallography Pub Date : 2024-07-01 DOI: 10.1515/pm-2024-0040

H. Schnarr

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Potential applications for modified Klemmsolutions 改良型 Klemmsolutions 的潜在应用

Practical Metallography Pub Date : 2024-07-01 DOI: 10.1515/pm-2024-0039

H. Schnarr

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Metallurgical failure investigation of small bore piping (SBP) in a diesel hydrotreating unit (DHT) of an oil refinery 炼油厂柴油加氢处理装置（DHT）中小口径管道（SBP）的冶金失效调查

Practical Metallography Pub Date : 2024-07-01 DOI: 10.1515/pm-2024-0046

E. Cagliyan, B. Fischer, M. Giller, A. Neidel

{"title":"Metallurgical failure investigation of small bore piping (SBP) in a diesel hydrotreating unit (DHT) of an oil refinery","authors":"E. Cagliyan, B. Fischer, M. Giller, A. Neidel","doi":"10.1515/pm-2024-0046","DOIUrl":"https://doi.org/10.1515/pm-2024-0046","url":null,"abstract":"\u0000 Hydrocarbon leaks were repeatedly found in the client’s refinery. Because of the recurring nature of this failure, the operator approached the authors’ laboratory to get a second opinion on the metallurgical root cause of the failure. It was known from the customer that corrosive species, such as ammonium chloride salt precipitates, are present in the subject diesel hydrotreating unit (DHT). From the findings obtained in the investigation that is the subject of this contribution, the conclusion of the original metallurgical root cause analysis (RCA), namely that the subject piping failed by transgranular chloride-induced stress corrosion cracking (Cl-SCC), could be verified and is indeed correct. The metallurgical root cause of the small bore piping (SBP) failure is chloride-induced SCC. The morphology of the cracking is very distinct and is clearly consistent with transgranular Cl-SCC. A material change to the nickel-base material Alloy 625, already considered by the client, since this alloy is believed to be immune to chloride-induced SCC, would be a good, even though expensive solution. It should be emphasized that there are no metallic materials completely resistant to SCC. If the environment is harsh enough, except for some titanium alloys, i. e., if the source of the chloride ions cannot be eliminated, which is likely the case here, a regular inspection and replacement of these SBP systems might have to be considered. It should further be emphasized that a chloride concentration below 50 ppm is by no means any guarantee for the avoidance of SCC, since chlorides can concentrate in crevices, corrosion pits and such, i. e., the local concentration is what matters, not the local.","PeriodicalId":508095,"journal":{"name":"Practical Metallography","volume":"10 24","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141846964","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}

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Attracting a new generation to materials science 吸引新一代加入材料科学

Practical Metallography Pub Date : 2024-07-01 DOI: 10.1515/pm-2024-0049

F. Hogue, M. Schleicher

{"title":"Attracting a new generation to materials science","authors":"F. Hogue, M. Schleicher","doi":"10.1515/pm-2024-0049","DOIUrl":"https://doi.org/10.1515/pm-2024-0049","url":null,"abstract":"\u0000 ASM International, an organization like DGM, has more than 15,000 members worldwide. The society was founded in 1913 as the Steel Treaters Club in Detroit. Their headquarters have been in the Cleveland, Ohio, area since 1920. ASM International has 6 Affiliate Societies including the International Metallographic Society.\u0000 In 1952 the need for a focused effort in education in Material Science was recognized and the ASM Materials Education Foundation (ASM Foundation) was established. Their mission is as follows: develop and deploy materials science content and hands-on, minds-on instructional strategies to inspire, engage, and empower future generations to create STEM (Science, Technology, Engineering, Mathematics) solutions for 21st century challenges.\u0000 The ASM Foundation has developed a multiprong approach to fulfil this mission and to draw young people to the field of materials science.\u0000 \u0000 \u0000 \u0000 Materials Camps for Students\u0000 \u0000 \u0000 Teacher Education and Empowerment\u0000 \u0000 \u0000 Mini Camps During Conferences\u0000 \u0000 \u0000 Expansion of Camps to Europe, India and Beyond\u0000 \u0000 \u0000 \u0000 In addition, the ASM Foundation awards scholarships to undergraduate and community college students in materials science.","PeriodicalId":508095,"journal":{"name":"Practical Metallography","volume":"10 14","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141846970","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}

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Inhalt 目录

Practical Metallography Pub Date : 2024-02-20 DOI: 10.1515/pm-2024-frontmatter3

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Characterization of microstructure and magnetic properties of 3D printed bonded magnets made by fused deposition modeling 通过熔融沉积建模制作的 3D 打印粘结磁体的微观结构和磁性能表征

Practical Metallography Pub Date : 2024-02-20 DOI: 10.1515/pm-2024-0013

M. Brunčko, A. Kneissl, L. Gorše, I. Anžel

{"title":"Characterization of microstructure and magnetic properties of 3D printed bonded magnets made by fused deposition modeling","authors":"M. Brunčko, A. Kneissl, L. Gorše, I. Anžel","doi":"10.1515/pm-2024-0013","DOIUrl":"https://doi.org/10.1515/pm-2024-0013","url":null,"abstract":"\u0000 Bonded magnets are composite materials consisting of polymer matrix and magnetic powders, prepared by rapid solidification processes from Nd-Fe-B alloys. They are synthesised by the compounding process on a twin-screw extruder, whereby, the finished products of complex shapes can be made from bonded magnets using injection moulding or 3D printing by fused deposition modelling method (FDM). The main advantages of 3D printing are the possibility to produce parts with complex geometries that are not possible with traditional manufacturing techniques and low-cost production of small batches.\u0000 The aim of the research work was to identify the optimum processing parameters, which would give 3D printed bonded magnets characteristics similar to those produced by injection moulding. The characterization of the microstructure of bonded magnets was made on cryo-fractured, conventionally mechanically prepared and ion beam polished samples. The microstructures of bonded magnets were analysed by stereo, optical and scanning electron microscopy. Additionally, the influence of the 3D printing parameters on the magnetic properties has been examined.\u0000 The results of the research work have shown that desired magnetic properties of 3D printed bonded magnets can be obtained by optimizing the thickness of the printed layer, printing speed and flowrate. In addition, it was revealed that selection of the materialographic preparation method plays a crucial step for correct microstructural characterization. Namely, the impropriate sample preparation results in artifacts that are mostly misinterpreted as microstructural defects (pores, cracks, non-adherent layers, etc.) accidently caused during 3d printing.","PeriodicalId":508095,"journal":{"name":"Practical Metallography","volume":"4 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139958314","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