WELDS

Author: BELLIDO PLA FÉLIX.
Year: 2004.
University: POLITÉCNICA DE MADRID [www.upm.es].
Place of defense: E.T.S. INGENIEROS INDUSTRIALES.
Place of preparation: E.T.S. INGENIEROS INDUSTRIALES.

Summary: Compared with standard methods with arc welding, laser welding has a number of potential advantages for the manufacture of structural components, such as the reduction of distortions, allowing reduce or even eliminate the need for enderezamientos subsequent higher welding speeds, improvements to the design, lower tolerances process, ease of automation and cost reduction. The development of high-power laser systems has enabled the implementation of court systems in many industries, including shipbuilding. Similarly happened in the case of welding processes, in which the laser replaced traditional ICT systems, MIG and MAG welding of components for the relatively small or small thicknesses. To the extent that they have started to be commercially available CO2 laser high power, reliability features / operation suitable for butt joints and T in carbon steels thickness greater than the 10mm, it has begun to consider as a the real alternative extension of their use in a wide range structural applications. However, the use of laser welding in shipbuilding requires prior demonstration of a large number of scientific and technological demands of its economic viability. A large number of projects and R & D activities in recent years have been coordinated with the aim of facilitating and accelerating this demonstration. This thesis focuses on the parameters of laser welding of CO2 from the perspective of shipbuilding, in terms of tolerances process / operation as quality and properties of the weld. In its development have looked different compositions of carbon steels, verifying the standards established by the Classification Societies Naval stages modeling termomecánica and elements of comparative analysis. The results allow in-depth analysis and positive with a view to the actual use of laser welding in shipbuilding. Keywords: laser welding parameters, welding with CO2 laser, laser welding, shipbuilding.

Author: MUÑEZ ALBA CLAUDIO JOSE.
Year: 2005.
University: REY JUAN CARLOS [www.urjc.es].
Place of defense: ESCUELA SUPERIOR DE CIENCIAS EXPERIMENTALES Y TECNOLOGÍA.
Place of preparation: ESCUELA SUPERIOR DE CIENCIAS EXP. Y TECNOLOGÍA.

Summary: Duplex stainless steels have become a great alternative to stainless steels auseteníticos conventional industries with highly aggressive environments. The excellent properties can be summarized in presenting a high mechanical strength and excellent resistance to corrosion, both located as low voltage. His combination of property and its competitive price, the lower Ni content of their composition, are the root causes of the continuing increase in the use of duplex stainless steels as structural materials in industries more aggressive. The properties of duplex stainless steels are best when the relationship between volumetric stages constituent (?/?) is near: 1:1. But this microstructural stock can be modified during shaped, especially in welding process, as a result of the precipitation of phases fragile, drastically altering the properties of the material. The manufacture of duplex stainless steels by pulvimetalúrgica (P / M), from powders of austenitic and ferritic stainless steel or adding elements austenizantes powder ferritic (the latter two are cheaper than the first), can be an alternative to conventional duplex stainless steel. The possibility of producing almost entirely shaped pieces I could do to reduce the number of welds required, and if this is a process of welding high-energy, which reduces the length of material thermally affected, can decrease the chances of change microstructural the material, and thus, the loss of property.