Metallography最新文献_第2页

Determination of the pearlite nodule size in eutectoid steels 共析钢中珠光体晶粒尺寸的测定

Metallography Pub Date : 1989-09-01 DOI: 10.1016/0026-0800(89)90015-3

Sergio Norifumi Doi , Hans-Jürgen Kestenbach

引用次数: 13

Influence of the composition and maximum cycling temperature on the microstructure of Cu-Al-Mn shape memory alloys 成分和最高循环温度对Cu-Al-Mn形状记忆合金显微组织的影响

Metallography Pub Date : 1989-09-01 DOI: 10.1016/0026-0800(89)90014-1

M.L. Blazquéz , C. López Del Castillo , C. Gómez

引用次数: 8

Microstructural corrosion behavior of austenitic Fe-21Mn-2.5Al-0.04C alloy in oxidizing-sulfidizing environments 奥氏体Fe-21Mn-2.5Al-0.04C合金在氧化硫化环境中的显微组织腐蚀行为

Metallography Pub Date : 1989-07-01 DOI: 10.1016/0026-0800(89)90041-4

S.C. Tjong

引用次数: 1

Microstructural analysis of an embrittled 422 stainless steel stud bolt after approximately 30 years service in a fossil power plant 422不锈钢螺柱螺栓在火电厂服役约30年后的微观结构分析

Metallography Pub Date : 1989-07-01 DOI: 10.1016/0026-0800(89)90039-6

Charlie R. Brooks, Ji-Peng Zhou

{"title":"Microstructural analysis of an embrittled 422 stainless steel stud bolt after approximately 30 years service in a fossil power plant","authors":"Charlie R. Brooks, Ji-Peng Zhou","doi":"10.1016/0026-0800(89)90039-6","DOIUrl":"10.1016/0026-0800(89)90039-6","url":null,"abstract":"<div><p>A microstructural analysis has been conducted of 12% Cr stainless steel (essentially Type 422) bolts that were found to be embrittled after service in a fossil-fired power plant for approximately 30 years at about 565–590°C. In the as-received condition, the Charpy V-notch absorption energy at 25°C was about 4 J. Fracture in the bolts and in the impact samples was intergranular, along the prior austenite grain boundaries. However, the fracture surfaces did have a fine, rough topology. The microstructure consisted of a rather uniform dispersion of fine particles in a ferrite matrix, with particles on the prior austenite grain boundaries. X-ray diffraction analysis of extracted particles, and TEM and STEM analysis of metallographic extraction replicas and thin foils, and of extraction replicas from the fracture surface, identified most of the particles as M<sub>23</sub>C<sub>6</sub> carbides. In addition, Laves phase and a Ni-rich (e.g., 30 wt. % Ni) phase were found.</p><p>Several heat treatments were tried to improve the toughness. The highest energy absorption of 34 J was obtained by reaustenitizing for 2 h at 1,065°C, oil quenching, then tempering for 2 h at 750°C, followed by air cooling. The microstructure was similar in appearance to that of the as-received, embrittled material. However, no Laves or Ni-rich phase was found. There was markedly less intergranular and more transgranular fracture.</p><p>The cause of the embrittlement was not discerned, nor why the toughness was improved with the heat treatments. A brief discussion of possible causes is presented.</p></div>","PeriodicalId":100918,"journal":{"name":"Metallography","volume":"23 1","pages":"Pages 27-55"},"PeriodicalIF":0.0,"publicationDate":"1989-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0026-0800(89)90039-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72776880","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: 9

Effect on the microstructure of aging Hastelloy B2 from 550 to 850°C for 1,200 hours 550 ~ 850℃时效1200小时对哈氏合金B2组织的影响

Metallography Pub Date : 1989-07-01 DOI: 10.1016/0026-0800(89)90040-2

Charlie R. Brooks, Y.M. Wang

{"title":"Effect on the microstructure of aging Hastelloy B2 from 550 to 850°C for 1,200 hours","authors":"Charlie R. Brooks, Y.M. Wang","doi":"10.1016/0026-0800(89)90040-2","DOIUrl":"10.1016/0026-0800(89)90040-2","url":null,"abstract":"<div><p>A microstructural examination (using optical and scanning electron microscopy) has been conducted of samples of a Hastelloy B2 alloy, which have been aged from 550 to 850°C for 200, 400, 800, and 1,200 hr. The nickel-based alloy contained 27.7% Mo, 1.0% Cr, 0.8% Fe, 0.3% Mn, and 0.002% C (wt. %). In the solution-annealed condition, the structure is facecentered cubic α. The study used samples of 50 and 800 μm initial α grain sizes. At all aging temperatures, the hardness increased and approximately doubled after aging for about 400 h at 550, 650, and 750°C. At 850°C, it was still increasing after 1,200 h. In the 50 μm initial grain-sized material, aging produced increasing amounts of a Widmanstatten plate structure, with the most prolific amounts at 750°C and the least at 550°C. The formation of this structure was considerably slower in the larger-grained size material since it initiated at the α grain boundaries. The initial formation was by a plate of high Mo content (relative to the matrix) surrounded by a region of low Mo content. This structure developed into a lamellar product, growing lengthwise by the movement of an interface. It appears that the plates are the γ phase (Ni<sub>3</sub>Mo). Since considerable hardening occurs even when the Widmanstatten structure is not prominent, it is believed that the α has, at least initially, transformed to the β phase (Ni<sub>4</sub>Mo), as this is known to cause hardening. The structures are discussed in terms of the known Ni-Mo-Fe and Ni-Mo-Cr ternary phase diagrams.</p></div>","PeriodicalId":100918,"journal":{"name":"Metallography","volume":"23 1","pages":"Pages 57-86"},"PeriodicalIF":0.0,"publicationDate":"1989-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0026-0800(89)90040-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76738657","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: 6

Surface preparation of aluminum for lon implantation 离子注入用铝的表面处理

Metallography Pub Date : 1989-07-01 DOI: 10.1016/0026-0800(89)90038-4

P.M. Natishan, G.T. Peace, P.F. Slebodnick

引用次数: 6

Characterization of weld solidification cracking in a duplex stainless steel 双相不锈钢焊接凝固裂纹的表征

Metallography Pub Date : 1989-07-01 DOI: 10.1016/0026-0800(89)90037-2

I. Varol, W.A. Baeslack III, J.C. Lippold

{"title":"Characterization of weld solidification cracking in a duplex stainless steel","authors":"I. Varol, W.A. Baeslack III, J.C. Lippold","doi":"10.1016/0026-0800(89)90037-2","DOIUrl":"https://doi.org/10.1016/0026-0800(89)90037-2","url":null,"abstract":"<div><p>Weld solidification cracking in the duplex stainless steel SAF 2205 has been investigated and compared with that of alternate duplex and austenitic stainless steels. Varestraint weld-ability testing showed SAF 2205 to exhibit a lower cracking susceptibility than that of the duplex stainless steel Ferralium 255 but greater than that of a Type 304 austenitic stainless steel which solidified as ferrite and exhibited Ferrite Number 8 (FN 8) in the weld fusion zone. The high augmented strain levels required to induce cracking in these three alloys during Varestraint testing indicated a high resistance to solidification cracking at strain levels normally encountered in structural weldments. Cracking susceptibilities of the duplex and Type 304/FN-8 stainless steels were appreciably lower than that of a Type 304L stainless steel which solidified entirely to austenite and exhibited less than FN 1 in the weld fusion zone.</p><p>Microstructural characterization of SAF 2205 using conventional black-and-white and two different color metallography techniques showed solidification cracks to be associated with ferrite grain boundaries. Color metallography was also effective in revealing the fusion zone solidification structure and delineating second phases, including inter- and intragranular austenite and fine Cr<sub>2</sub>N precipitates. Fractographic analysis of solidification crack surfaces from SAF 2205 Varestraint samples revealed dendritic and flat topographies, and confirmed a solidification versus solid-state cracking mechanism.</p></div>","PeriodicalId":100918,"journal":{"name":"Metallography","volume":"23 1","pages":"Pages 1-19"},"PeriodicalIF":0.0,"publicationDate":"1989-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0026-0800(89)90037-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"137344961","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

Transmission electron microscopy of icosahedral phase in Al-Li-Cu alloys Al-Li-Cu合金中二十面体相的透射电镜研究

Metallography Pub Date : 1989-05-01 DOI: 10.1016/0026-0800(89)90010-4

J.R. Reed , D.J. Michel , A.K. Singh

引用次数: 0

Silicon-induced destabilization of galvanized coatings in the sandelin peak region 硅致镀锌层在sandelin峰区失稳

Metallography Pub Date : 1989-05-01 DOI: 10.1016/0026-0800(89)90006-2

M.S Kozdras, P Niessen

引用次数: 23

Metallographic cross sections and scanning electron microscopy as analytical tools in the failure analysis of rectifiers 金相截面和扫描电镜作为分析工具在整流器失效分析中的应用

Metallography Pub Date : 1989-05-01 DOI: 10.1016/0026-0800(89)90002-5

Mikelis V. Veidis

引用次数: 3