Aplicação de cavacos de titânio para produção de revestimentos resistentes ao desgaste

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

Avaliação da integridade estrutural em um tubo de aço API 5L X70 através da propagação de trincas por fadiga

Pós-graduação em Engenharia Mecânica - FEG

Avaliação da tenacidade CHARPY-V de um tubo de aço API 5L X70 soldado com arco submerso

This research project focused primarily on assessing the impact toughness of the weld and the base material of a steel pipe API 5L X70 submerged arc welded, used to conduct remote oil and gas (linepipes). The analysis followed strictly the Specification for Line Pipe - API 5L Standard, regarding the removal of the specimens of regions-of-proof-long section of the pipe, at 90o and 180o from the welded joint, and mechanical properties of toughness and Charpy-V, both the joint welded as the base material. Specimens of steel tube supplied by Tenaris Confab-SA were sized for tensile and Charpy-V, according to ASTM E 8M and ASTM E23, respectively. The result obtained showed that the API X70 steel tube has high Charpy-V toughness, near to each other at both 90o and 180o from the welded joint of the tube, and both higher than the weld metal. Microstructural and microhardness analysis complemented the present study

Determinação experimental da tenacidade à fratura em baixas temperaturas de tubos de aço API 5L X70

Because of the great metallurgical advances, the welded tubes by HF / ERW (High Frequency / Electrical Resistance Welding) have played a more active role in the oil and gas, gradually replacing tubes produced by other processes (UOE, SAW, and others) to deep water applications, in high and extremely low temperatures, highpressure conditions and in highly corrosive environments. However, studies have revealed that defects in the welded joints are in one of main causes of failures in pipelines. Associated with damage external and the stringent requirements of this sector, the welded joints become particularly critical for his toughness and the determination of this particular property is fundamental. This study aims to evaluate the toughness of the HF / ERW pipes in HSLA steel API X70 class, used in pipelines transport systems of gas and oil from data obtained with CTOD tests (Crack Tip Opening Displacement). The main objectives of this project are: mechanical and microstructural characterization of steels API X70 manufactured in Brazil; and evaluation of the toughness of weld process by HF / ERW steel API X70 national. After having the tests done, mechanical, chemical and metallurgical, we have the conclusion that those pipe are in agreement to API 5L 42ª edition for X70MO and the toughness behaves like the expected

Investigação experimental da tenacidade em tubos de aço API 5L X70 soldados pelo processo HF/ERW

Studies about structural integrity are very important when it desires to prevent disasters associated with flaws inherent in materials used in structural components. The welded joints in steel pipes used to conduction and distribution of oil and gas correspond to the regions most susceptible to flaw. Aiming to contribute to this research line, the present study was designed to assess experimentally the structural integrity of welded joints in steel pipes API 5L X70 used in pipeline systems. This assessment is given from tests of CTOD, whose aim is simulate in laboratory the real behaviour of crack from of his propagation on the welded joint obtained by high frequency electric resistance welding. In this case, the analyses are performed from specimens SE(B) obtained directly of steel pipe API 5L X70. The proposed methodology involves tests of CTOD at lower temperature, in order to assess the toughness of material in critical operation conditions. From performance of CTOD tests, was possible assess the toughness of welded joints in terms of quantity through CTOD parameter and in terms of quality from behaviour of curve load versus CMOD. In this study, also, sought to compare CTOD’s results obtained through rules ASTM E1820 (2008) and BS 7448 (1991). Although the two standards cited previously have adopted different parameters to calculated the value of CTOD, concluded that the values of CTOD tend to converge for a common value

Análise microestrutural de tubos API P110, para prospecção de petróleo e gás, soldados pelo processo HF/ERW

On the grounds of the great advances achieved over recent years, the process HF/ERW (High-Frequency/Electric Resistance Welding)welded pipe have played an active role in the oil and gas industry for deep water applications, at high and extremely low temperatures, under high pressure and in highly corrosive environments, gradually replacing manufactured pipes by other processes. However, studies have shown that defects in the welded joints are a the leading causes of pipelines failures, which has required the determination of toughness values in this region, in compliance with the strict recommendations of the codes and standards with manufacturers and construction companies, on the oil and gas sector. As part of the validation process required toughness values, this research project focuses on a microstructural analysis in HF / ERW tubes microalloyed, steel grade API 5CT P110, designed to explore oil and gas in deep waters, the subject of strategic relevance to the country because of the recent discoveries in the Santos mega fields: Tupi and Libra (pre-salt). In this scientific work will be presented and discussed the results of mechanical tensile and Charpy, a few CTOD tests curves (showing the trend of toughness values to be obtained), and the microstructures of the base material obtained by optical microscopy, with special emphasis on the formation of nonmetallic inclusions in the welded joint

Identificação de causas especiais no processo que aumentam a ocorrência de poro na solda de tubos de aço: aplicação etapas definir, medir e analisar do DMAIC

This work covers the methodology Six Sigma with the application of the steps Define, Measure and Analyze a company of steel tubes, with the objective of identify special causes in the process that drives the creation of the pore defect in the solder. It is highlighted the fact that this work is the base of an continuous upgrade project that aims in eliminating the occurrence of this defect. The motivation is given to the necessity of improving the productivity of the factory, considering that the defect occurs at random and your causes are unknown. This way, it was defined that the problem to analyze, measured the capability of the process in DPMO and analyzed with the aid of graph by attribute P. The results show the process that present special cases, as well as the process considered ideal, This way it was stated that in this work, the processes destabilized and the controlled, allowing a comparison of the characteristics for the elaboration of concise action plans to eliminate the defect. The project must follow the steps Upgrade and control the methodology Six Sigma, in order to ensure success in his execution, aiming to amplify the competitive edge of the business

Avaliação da tenacidade à fratura em juntas soldadas circunferenciais de tubulações de processo

This work aims to analyze the toughness of a welded joint in the presence of a crack through the analysis of maximum tension the material can withstand the presence of this type of defect, since a discontinuity is likely to occur in this type of joint and its detection and its design is simple, using non-destructive testing techniques. The study will be conducted through the CTOD test - Crack-Tip Opening Displacement, with type specimens SE (B) - Single Edge Bend taken from a weld in the L-C position in relation to the length (longitudinal axis) of a test tube. The main idea is to simulate the welding conditions for the manufacture of industrial pipes, made in boiler shops (pipe-shop) within petrochemical plants. These pipes are often subject to operation with flammable and toxic subjected to high pressures and temperatures, where one can break the line can cause irreparable damage to the plant, the environment and the health of surrounding communities. With this study we evaluate whether the weld metal has the same properties as fracture toughness of the base material. This study shows the importance of using a qualified welding procedure for performing quality welds while maintaining the properties of the fracture toughness of the base metal. It was found from the results of tests using a welding procedure described for carrying out welding ensures mechanical properties very close to the base metal, which in terms of design is great, since one can ensure that the weld will the same characteristics of the base metal specified for the assembly of the pipe

Avaliação de juntas soldadas em tubos de aço carbono submetidos a altas temperatura e pressões

The welding process in industrial piping is still the most effective way to ensure the durability and quality of the wide range of industrial process, although because of the high demand for energy and quality of the produced products, the piping has been constantly tested for high pressure applications and still high temperature. The welding method analyzed is the TIG (Tungsten Inert Gas) welding or GTAW (Gas-Shielded Tungsten Arc Welding), which ones have as principal feature the utilization of a not consumable tungsten electrode in the torch extremity , in this process is necessary a protective atmosphere of inert gas. The welding TIG advantage is the obtaining of a welded seam clean and with quality for not has slag after the welding. This work has as objective show the variability in the carbon steel piping welding parameters and by the tests in four proof bodies will be shown the influence of the variation of the welding methods in a welded seam. The tests will vary since the piece to be welded preparation, till penetrating liquid tests, welding macrography, welding x-ray and traction tests. Even been a clean and with quality welding is necessary a final inspection in the seam welded looking for defects almost inevitable resulted of the welded process, the obtained results have the objective of indicate and minimize the defects to ensure quality and durability of the welded seam

Caracterização microestrutural de uma estrutura tubular aeronáutica submetida a sucessivos reparos de solda TIG

This work examines the possible effects of successive repair procedures on the microstructure of welded steel SAE 4130 by TIG welding process. Discussions and results were made about the metallographic analysis , non-metallic inclusions and microhardness tests , which were conducted on samples taken from the cradle engine component after the end of its life , a model airplane T-27 Tucano , made by EMBRAER and belonging were performed FAB . The choice of such component is due to the fact that this is critical to flight safety since it provides support for the aircraft engine . Thus regions of the weld metal , base metal and heat affected , with samples of the original weld bead , free of weld bead and also with four rework procedures for TIG welding zone were analyzed . It was found that after the fourth rework there is an increase in the amount of martensite , which may weaken the material with respect to resistance to fatigue. It was also found that the regions of the heat affected zone and weld metal have higher microhardness values when compared to those found in the base metal due to favoring the formation of ferritic and tempered martensite microstructures . Moreover, a welding process promotes a region with less non-metallic inclusions than metal base , which also explains the difference in the results obtained

Analise mecânica e microestrutural em estruturas tubulares aeronáuticas soldadas de aço ABNT 4130

Airplane Motor Cradles have a complex geometry, since they require different conbinations between different tubes and TIG welded in several angles. In T-25 aircraft and Universal T-27 Tucano (EMBRAER / FAB), besides having to bear the engine balance, these components maintain fixed the nose landing gear in another extremity. They are considered critical to flight safety, and for this reason, the aviation standards are extremely rigid in their production, imposing a zero index” of defects on the final weld metal quality. These structures may be containing an historical of welding repairs, whose effects on their structural integrity are not computed. In this work we analyzed the standardised AISI 4130 steel and the raw steel of tubes to the Airplane Motor Cradles. First of all, microscopy and microanalysis of the base steel, then we analyzed the effects of the TIG weld. Tensile testing was conducted to measure the difference between the mechanical properties of standardised steel and without this treatment

Alterações microestruturais decorrentes dos sucessivos reparos de solda TIG aplicados ao longo da vida útil de uma estrutura aeronáutica crítica à segurança de vôo

The steel type AISI 4130 (ultra-high strength steel) is an alloy of low carbon and its main alloying elements are chromium and molybdenum, which improves the toughness of the weld metal. It has numerous applications, especially where the need for high mechanical strength. It is widely used in equipment used by the aviation industry, such as cradle-tomotor, and this is the motivation for this study. Cots are of fundamental importance, because the engine supports and maintains balance in the fixed landing gear. This equipment is subjected to intense loading cycles, whose fractures caused by fatigue are constantly observed. Will be determined the effects caused by re-welding the structure of aeronautical equipment, and will also study the microstructure of the metal without welding. The studies will be done on materials used in aircraft, which was given to study. The results provide knowledge of microstructure to evaluate any type of fracture that maybe caused by fatigue. Fatigue is a major cause of aircraft accidents and incidents occurred, which makes the study of the microstructure of the metal, weld and re-solder the knowledge essential to the life of the material. The prevention and control of the process of fatigue in aircraft are critical, since the components are subjected to greater responsibility cyclic loading

Fabricação de rodas: uma análise comparativa

In our country, the majority of freight and people by road happens municipal, state and federal. Thus, the heavy vehicles like buses and trucks are the main means of transporting people and cargo. This graduate work aims to study the process of manufacturing wheels for trucks, because we can see the lack of literature on the manufacturing process of wheels and also the importance of the processes used to manufacture wheels, such as lamination, stamping, puckering, machining, welding and painting

Criação de novo procedimento de engenharia que possibilite a rastreabilidade das tubulações de uma indústria química

The number of piping in an industry is high. Through this piping are conducted several kind of products at several temperature and pressure conditions. In a chemical company, the piping quantity conducting harmful chemical products to human health and to the environment is higher. Nowadays the theme sustainability is often mentioned and harm to environment may cause irreversible damage to the human being, to the fauna, to the flora and to company´s credibility. In this context, controlling over the piping to avoid accidents is mandatory. The objective of this monograph is to create a procedure which enables the chemical companies piping traceability. This monograph analyses the several existent traceability system in the three economy sectors and approaches the technical question of industrial piping in order to create a procedure that achieves its objectives as a technical document and at the same time be economically feasible, with low complexibility level and high practicability. Some possibilities to elaborate this procedure had been studied, as the creation of an alphanumeric code and making with a chisel in the pipeline based on ASTM F2897 and the use of chips to store the information. However, the procedure which best meet the requirement as low cost and high applicability is filling out an electronic plan with information about welding process, welding certification, welding consumables and inspections

Estudo do comportamento em fadiga de um tubo de aço API 5CT soldado por resistência elétrica

The oil extraction in deep waters sparked new areas of knowledge, the creation of engineering courses dedicated just to these processes and a wide field of analysisvoiding multiple impacts in case of faults, mainly the economic and environmental. This paper aims to show on the effects and causes of fatigue failure in steel tubes used for oil and gastransportation (linepipe), mainly caused by vortex induced vibrations, or VIV. To make this, through laboratory tests, it found trough the curve Stress versus Number of Cycles, and thus estimating that with a stress value of 350 MPa or less, the fatigue life cycle of the API 5CT T95 (1% Cr) pipe is estimated infinite. It could conclude that the analyzed material has good fatigue failure resistance for offshore use, taking into account only the influence of VIV's, since there are no stress concentrators