The Experts below are selected from a list of 1554 Experts worldwide ranked by ideXlab platform

Rafael Colás - One of the best experts on this subject based on the ideXlab platform.

  • Forming of seamless Pipe Fittings
    Journal of Materials Processing Technology, 2002
    Co-Authors: A. Rodriguez, P. Fodor, Margarita Mezzetti, Rafael Colás
    Abstract:

    Abstract Analysis and results of the high temperature forming of seamless Pipe Fittings produced at a local factory are presented in this work. The studies were conducted by recording the thermal evolution in different parts of the piece as it was being forged, which was done by placing a series of type K thermocouples within the part and logging the data into a computer driven system. The initial trials put in evidence the need to change the heating practice in order to ensure a greater thermal homogeneity. Metallographic evaluation was carried out on formed pieces to study variations in their microstructure before and after the changes in the heating practice were made. Modification of this practice resulted in improvements in quality, such as the reduction in the variation in microstructure and wall thickness, as well as an increase in productivity, as the pressing speed was augmented.

  • Strain distribution analysis of hot forged seamless Pipe Fittings
    Materials Science and Technology, 2000
    Co-Authors: A. Rodriguez, G. Olvera, P. Fodor, Rafael Colás
    Abstract:

    AbstractA strain distribution analysis was carried out on hot forged seamless Pipe Fittings produced at a factory. The studies were conducted on Pipe preforms, cut from a seamless Pipe, which had a grid inscribed on the outside surface. The dimensions of the individual cells were measured before processing of the preforms and, once the parts had cooled down to room temperature, the dimensions of the distorted grids were recorded. The different components of strain were evaluated from both sets of measurements. Thermal evolution during forging was recorded by inserting a series of type K thermocouples into the preforms and logging the data into a computer system. Two preforms were loaded together in a single trial, whereas a third one was deformed by itself to evaluate the consistency of the process. Results from the analysis compare favourably with measurements of the change in wall thickness obtained by ultrasonic means in one of the pieces.

A. Rodriguez - One of the best experts on this subject based on the ideXlab platform.

  • Forming of seamless Pipe Fittings
    Journal of Materials Processing Technology, 2002
    Co-Authors: A. Rodriguez, P. Fodor, Margarita Mezzetti, Rafael Colás
    Abstract:

    Abstract Analysis and results of the high temperature forming of seamless Pipe Fittings produced at a local factory are presented in this work. The studies were conducted by recording the thermal evolution in different parts of the piece as it was being forged, which was done by placing a series of type K thermocouples within the part and logging the data into a computer driven system. The initial trials put in evidence the need to change the heating practice in order to ensure a greater thermal homogeneity. Metallographic evaluation was carried out on formed pieces to study variations in their microstructure before and after the changes in the heating practice were made. Modification of this practice resulted in improvements in quality, such as the reduction in the variation in microstructure and wall thickness, as well as an increase in productivity, as the pressing speed was augmented.

  • Strain distribution analysis of hot forged seamless Pipe Fittings
    Materials Science and Technology, 2000
    Co-Authors: A. Rodriguez, G. Olvera, P. Fodor, Rafael Colás
    Abstract:

    AbstractA strain distribution analysis was carried out on hot forged seamless Pipe Fittings produced at a factory. The studies were conducted on Pipe preforms, cut from a seamless Pipe, which had a grid inscribed on the outside surface. The dimensions of the individual cells were measured before processing of the preforms and, once the parts had cooled down to room temperature, the dimensions of the distorted grids were recorded. The different components of strain were evaluated from both sets of measurements. Thermal evolution during forging was recorded by inserting a series of type K thermocouples into the preforms and logging the data into a computer system. Two preforms were loaded together in a single trial, whereas a third one was deformed by itself to evaluate the consistency of the process. Results from the analysis compare favourably with measurements of the change in wall thickness obtained by ultrasonic means in one of the pieces.

P. Fodor - One of the best experts on this subject based on the ideXlab platform.

  • Forming of seamless Pipe Fittings
    Journal of Materials Processing Technology, 2002
    Co-Authors: A. Rodriguez, P. Fodor, Margarita Mezzetti, Rafael Colás
    Abstract:

    Abstract Analysis and results of the high temperature forming of seamless Pipe Fittings produced at a local factory are presented in this work. The studies were conducted by recording the thermal evolution in different parts of the piece as it was being forged, which was done by placing a series of type K thermocouples within the part and logging the data into a computer driven system. The initial trials put in evidence the need to change the heating practice in order to ensure a greater thermal homogeneity. Metallographic evaluation was carried out on formed pieces to study variations in their microstructure before and after the changes in the heating practice were made. Modification of this practice resulted in improvements in quality, such as the reduction in the variation in microstructure and wall thickness, as well as an increase in productivity, as the pressing speed was augmented.

  • Strain distribution analysis of hot forged seamless Pipe Fittings
    Materials Science and Technology, 2000
    Co-Authors: A. Rodriguez, G. Olvera, P. Fodor, Rafael Colás
    Abstract:

    AbstractA strain distribution analysis was carried out on hot forged seamless Pipe Fittings produced at a factory. The studies were conducted on Pipe preforms, cut from a seamless Pipe, which had a grid inscribed on the outside surface. The dimensions of the individual cells were measured before processing of the preforms and, once the parts had cooled down to room temperature, the dimensions of the distorted grids were recorded. The different components of strain were evaluated from both sets of measurements. Thermal evolution during forging was recorded by inserting a series of type K thermocouples into the preforms and logging the data into a computer system. Two preforms were loaded together in a single trial, whereas a third one was deformed by itself to evaluate the consistency of the process. Results from the analysis compare favourably with measurements of the change in wall thickness obtained by ultrasonic means in one of the pieces.

Gisle Rørvik - One of the best experts on this subject based on the ideXlab platform.

  • Influence of sigma-phase precipitation on the impact behaviour of duplex stainless steel Pipe Fittings
    Ships and Offshore Structures, 2014
    Co-Authors: Tore Børvik, Lene Anita Marken, Magnus Langseth, Gisle Rørvik, Odd Sture Hopperstad
    Abstract:

    In this study, the effect of sigma-phase precipitation in duplex stainless steel (grade 2205) Pipe Fittings collected from top-side process systems offshore was investigated under realistic loading conditions. This was done by conducting quasi-static and dynamic impact tests on 3” Fittings with a nominal outside diameter of 88.9 mm, nominal wall thickness of 3.05 mm and D/t-ratio of nearly 30. The Fittings had a sigma-phase level between 0 and 15 vol.%, and were loaded by a massive steel indenter with a hemispherical nose of 25 mm radius. In the quasi-static tests, the loading rate was 2 mm/min, while in the dynamic tests the impact velocity was varied between 5 and 10 m/s. A few dynamic impact tests on 2” Fittings with an increased wall thickness and low sigma-phase levels were carried out for comparison, while some 3” Fittings were pre-charged with hydrogen before dynamic testing to examine the effect of sigma phase on cathodic protected subsea components. When the sigma-phase level was low (i.e. σ ⩽ 5 ...

  • Pipe Fittings in duplex stainless steel with deviation in quality caused by sigma phase precipitation
    Materials Science and Engineering: A, 2010
    Co-Authors: Tore Børvik, Hans I. Lange, Lene Anita Marken, Magnus Langseth, Odd Sture Hopperstad, M. Aursand, Gisle Rørvik
    Abstract:

    Abstract Pipe Fittings in duplex stainless steel (grade 2205) are used both top-side and subsea by the oil industry offshore. Precipitation processes during heat treatment of such Fittings may result in various detrimental intermetallic phases and carbides. Among these defects, the sigma phase has a particular interest since it already in small amounts may cause a considerable reduction in mechanical properties and corrosion resistance of the material. To study the influence of sigma phase content on the stress–strain behaviour and ductility under quasi-static and dynamic loading conditions, tensile tests at room temperature (+20 °C) and low temperatures (−46 °C, −10 °C) were carried out for duplex stainless steel with varying levels of sigma phase (∼0 vol.%, 1–5 vol.%, ∼10 vol.%). Specimens pre-charged with hydrogen were also tested to study the influence of sigma phase on cathodic protected subsea components. In addition, fracture toughness tests (CTOD) on single-edge notch bend specimens and Charpy impact tests on V-notched specimens at various temperatures were conducted to establish the influence of sigma phase on the toughness of the material.

Petros C Mavroidis - One of the best experts on this subject based on the ideXlab platform.