A influência de modificações superficiais no aço 1045 formadoras de compostos de Fe-Sn quanto à permeação de hidrogênio

O objetivo deste trabalho foi estudar e desenvolver uma técnica que diminuísse a concentração de hidrogênio absorvido pelo aço SAE 1045. A técnica consistiu na modificação superficial de amostras de aço SAE 1045 através de eletrodeposição de Sn na superfície com posterior tratamento térmico para promover a difusão do Sn para o interior do aço. Por meio da técnica de RBS, foram caracterizados os perfis de concentração do Sn no aço com a profundidade. Por outro lado, com o uso da técnica de permeação eletroquímica, aplicada tanto em meio alcalino como neutro, foi avaliada a eficiência das modificações superficiais em inibir a absorção do hidrogênio pelo aço. Foram constatadas significativas reduções da absorção de H em amostras modificadas com a adição de 100nm de Sn eletrodepositado com posterior difusão. Utilizou-se também medidas de impedância eletroquímica e ensaios de voltametria potenciostática e potenciodinâmica para descrever as influências das modificações superficiais no processo de absorção.

Hydrogen embrittlement in an AISI 1045 steel component of the sugarcane industry

This paper will present a failure analysis of a chain component, manufactured with AISI 1045 steel and used for sugarcane transport. During the fabrication process, this component is submitted to induction hardening, just on one surface, before the galvanizing process. The occurrence of surface cracks, during storage, disables the usage of these components. Chemical and metallographic analyses, tensile, fracture toughness, and hardness tests, and fractography were conducted in order to determine the causes of failure. The steel chemical composition was in accordance with AISI 1045. The metallographic analyses and fractography did not exhibit the presence of zinc into the cracks; this is an indication that the cracks occurred after the galvanizing process. Tensile and fracture toughness test results are as expected. The crack surface and the fracture toughness specimen surfaces showed two different fracture micromechanisms: dimples and intergranular. The delayed fracture associated with the predominance of intergranular fracture micromechanism at the induction hardened layer and the high hardness level is a clear indication of the hydrogen embrittlement. (c) 2008 Elsevier Ltd. All rights reserved.

SAE 1045 steel/WC-Co/Ni-Cu-Ni/SAE 1045 steel joints prepared by dynamic diffusion bonding: Microelectrochemical studies in 0.6 M NaCl solution

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Energia específica de corte e integridade superficial no microfresamento do ABNT 1045

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influência do tratamento térmico sobre a tenacidade de um aço com AISI SAE 1045 com médio teor de carbono, avaliada por ensaios de impacto

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

The Probe, Issue 171 – November 1996

Park Service Thwarts Cat Allies, by Marilyn Davis, Native Species Network, Bodega Bay, California Jim Miller Elected VP of Wildlife Society ADC Aerial Hunting Accident Kills 2 Obituary: Carl R. Gustavson HSUS Former Employee File Lawsuits Rats Shut Down Internet at Stanford Call for Papers: A Symposium on Mammal Trapping August 1997 in Edmonton, Alberta Fur in Cyberspace: The Fur Institute of Canada announces it has established a site on the World Wide Web, at the following address: http://www.fur.ca. Book Review: Beaver and Otter: Open Water Techniques, by Charles Dobbins 1992. Beaver Pond Publishing and Printing, P.O. Box 224, Greenville, Pennsyulvania, 16125. 114 pages. American Association of Wildlife Veterinarians: Resolution on Management of Feral Cats Use of Zinc Phosphide for Marmot Control, by Mark Collinge, NADCA Northern Rockies Region Director, USDA-APHIS-ADC Cat Colony Ordinance Adopted by Santa Clara County, California

Caprine PRNP polymorphisms at codons 171, 211, 222 and 240 in a Greek herd and their association with classical scrapie

The association between PRNP variation and scrapie incidence was investigated in a highly affected Greek goat herd. Four mutations were identified at codons 171Q/R, 211R/Q, 222Q/K and 240P/S. Lysine at codon 222 was found to be associated with the protection from natural scrapie (P=0.0111). Glutamine at codon 211 was observed in eight animals, all of them being scrapie-negative, indicating a possible protective role of this polymorphism although statistical analysis failed to support it (P=0.1074). A positive association (P=0.0457) between scrapie-affected goats and the wild-type Q(171)R(211)Q(222)S(240) allele is presented for the first time. In addition, a novel R(171)RQS allele, which is identical to the A(136)R(154)R(171) allele that has been associated with resistance to classical scrapie in sheep, was observed in low frequency. Resistant alleles that include K(222) and Q(211) are absent or rare in sheep and can provide the basis for the development of a feasible breeding programme for scrapie eradication in goats.

Ms. hebr. oct. 171 - [Sammelband in 2 Teilen: Handschriftenkonvolut]

Vorbesitzer: Eljāqīm Carmoly

Ms. Barth. 171 - Niederländischer Katechismus

Vorbesitzer: Bartholomaeusstift Frankfurt am Main

Na 50 Nachlass Arthur Schopenhauer - 'Schopenhauer-Archiv', 1045 - Satzung der Königlich Norwegischen Gesellschaft der Wissenschaften (Leges, quas sibi scripsit regia scientiarum societas Norvegiae, ab augustissimo rege indulgentissime sanctitae)

12 Seiten

Na 50 Nachlass Arthur Schopenhauer - 'Schopenhauer-Archiv', 171 - Glückwunsschreiben von Carl von Knyphausen zum 70. Geburtstag

u.a.: Besuch bei Schopenhauer;

Ms. Praed. 171 - Collectanea et excerpta theologica

Vorbesitzer: Dominikanerkloster Frankfurt am Main