Avaliação da soldagem GMAW mecanizada e automatizada para união de dutos utilizando fontes convencional e com controle de curto- circuito

Welding is one of the most employed process for joining steel pipes. Although, manual welding is still the most used one, mechanized version and even automatized one have increased its demand. Thus, this work deals with girth welding of API 5L X65 pipes with 8” of nominal diameter and 8.0 mm thickness, beveled with V-30º narrow gap. Torch is moved by a bug carrier (mechanized welding) and further the parameters are controlled as a function of angular position (automatized welding). Welding parameters are presented for filling the joint with two-passes (root and filling/capping passes). Parameters for the root pass were extracted from previous author´s work with weldments carried out in plates, but validated in this work for pipe welding. GMAW processes were assessed with short-circuit metal transfer in both conventional and derivative modes using different technologies (RMD, STT and CMT). After the parameter determination, mechanical testing was performed for welding qualification (uniaxial tension, face and root bending, nick break, Charpy V-notch impact, microhardness and macrograph). The initially obtained results for RMD and CMT were acceptable for all testing and, in a second moment, also for the STT. However, weld beads carried out by using the conventional process failed and revealed the existence of lack of fusion, which required further parametrization. Thus, a Parameter-Variation System for Girth Welding (SVP) was designed and built to allow varying the welding parameters as a function of angular position by using an inclinometer. The parameters were set for each of the three angular positions (flat, vertical downhill and overhead). By using such equipment and approach, the conventional process with parameter variation allowed reducing the welding time for joint accomplishment of the order of 38% for the root pass and 30% for the filling/capping pass.

Do trabalho de Deus... Adeus ao trabalho? Ontologia, precarização, controle do trabalho e fetichismo em A caverna de José Saramago

The aim of this study is to undertake a theoretical analysis of the literary and sociological Cave, Jose Saramago, having as main theme the precariousness of work and control, followed by some key developments. Anchored in the sociology of work and endorsed by the sociology of literature methodologically by Antonio Candido, and guided by the narrative Saramago in the cave, seeking to understand the work activity as central and essential to the production and reproduction of material life. It discusses the precariousness of work, as well as the historical forms of ownership and control of labor activity. Scales the impact of large corporations that control and the conflict between mechanized and manual labor in the process, questioning the nefarious effects of the restructuring of the productive working class, especially on small businesses and craft work. It also addresses the rise of a category gestorial in the process of labor control throughout history Finally, invoking the metaphor of Plato\'s cave in this work Saramago, explores how labor control by large corporations causes the estrangement in all dimensions of life, establishing relationships between fetishism, consumer relations and sociability.