Ferritic stainless steel welding with the A-TIG process

O processo de soldagem TIG com fluxo (processo A-TIG) apresenta como principal vantagem a possibilidade de se obter uma maior penetração do cordão de solda empregando os mesmos parâmetros de soldagem do processo TIG convencional. Diversos estudos mostram a influência dos fluxos ativos sobre as características geométricas das soldas em aços inoxidáveis austeníticos, porém pouco se sabe sobre a influência deste processo nas características geométricas e metalúrgicas de cordões de solda em aços inoxidáveis ferríticos. Neste trabalho são aplicados diferentes tipos de fluxo na soldagem de aço inoxidável ferrítico com o objetivo de verificar possíveis influências no perfil do cordão de solda, no seu aspecto visual, na microestrutura, na dureza da zona fundida e na resistência ao impacto (ensaio Charpy). As soldagens "bead-on-plate" foram realizadas sem metal de adição. Foram utilizados seis tipos de fluxo, sendo um óxido elaborado em laboratório (TiO2) e cinco fluxos comerciais. Os resultados mostraram que a utilização do fluxo permite um aumento na penetração com mudanças significativas no aspecto do cordão de solda. Verificou-se ainda que a microestrutura e a dureza do cordão de solda do aço estudado não foram afetadas pelo tipo de fluxo utilizado, com a microestrutura analisada em microscópio óptico. O aço em estudo mostrou um alto grau de fragilidade à temperatura ambiente._________________________________________________________________________________________ RESUMO: The A-TIG welding process presents as main advantage the possibility of increase in the penetration depth using the same parameters as conventional TIG welding. Many researchers show the influence of the active flux on the weld geometry in austenitic stainless steel, however little it is known of the influence of this process in the weld fillet shape and metallurgic characteristics of the weld fillet in ferritic stainless steel. In this work different types of flux are applied with the objective to verify possible influences on the weld fillet in ferritic stainless steel welding, such its visual aspect, the microstructure, the hardness and resistance to the impact of the fusion zone. Bead on plate welds were made without metal filler. Six types of flux had been used, and one flux was prepared in laboratory (TiO2) and the others five were commercial flux. The results indicate that the use of the flux allows increase in the penetration with significant changes in the aspect of the weld fillet. It was verified that the microstructure and the hardness of the weld fillet of this ferritic stainless steel was not been affected by the flux type. The result of the Charpy test in the metal base it was batter in the fusion zone

NEOTROPICAL XENARTHRANS: a data set of occurrence of xenarthran species in the Neotropics

Xenarthrans – anteaters, sloths, and armadillos – have essential functions for ecosystem maintenance, such as insect control and nutrient cycling, playing key roles as ecosystem engineers. Because of habitat loss and fragmentation, hunting pressure, and conflicts with 24 domestic dogs, these species have been threatened locally, regionally, or even across their full distribution ranges. The Neotropics harbor 21 species of armadillos, ten anteaters, and six sloths. Our dataset includes the families Chlamyphoridae (13), Dasypodidae (7), Myrmecophagidae (3), Bradypodidae (4), and Megalonychidae (2). We have no occurrence data on Dasypus pilosus (Dasypodidae). Regarding Cyclopedidae, until recently, only one species was recognized, but new genetic studies have revealed that the group is represented by seven species. In this data-paper, we compiled a total of 42,528 records of 31 species, represented by occurrence and quantitative data, totaling 24,847 unique georeferenced records. The geographic range is from the south of the USA, Mexico, and Caribbean countries at the northern portion of the Neotropics, to its austral distribution in Argentina, Paraguay, Chile, and Uruguay. Regarding anteaters, Myrmecophaga tridactyla has the most records (n=5,941), and Cyclopes sp. has the fewest (n=240). The armadillo species with the most data is Dasypus novemcinctus (n=11,588), and the least recorded for Calyptophractus retusus (n=33). With regards to sloth species, Bradypus variegatus has the most records (n=962), and Bradypus pygmaeus has the fewest (n=12). Our main objective with Neotropical Xenarthrans is to make occurrence and quantitative data available to facilitate more ecological research, particularly if we integrate the xenarthran data with other datasets of Neotropical Series which will become available very soon (i.e. Neotropical Carnivores, Neotropical Invasive Mammals, and Neotropical Hunters and Dogs). Therefore, studies on trophic cascades, hunting pressure, habitat loss, fragmentation effects, species invasion, and climate change effects will be possible with the Neotropical Xenarthrans dataset