The Experts below are selected from a list of 6087 Experts worldwide ranked by ideXlab platform

Ke Yang - One of the best experts on this subject based on the ideXlab platform.

  • Lath boundary thin-film martensite in acicular ferrite ultralow carbon pipeline steels
    Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2005
    Co-Authors: Ming-chun Zhao, Toshihiro Hanamura, Hai Qiu, Ke Yang
    Abstract:

    Modern pipeline technology for the production of oil and gas pipeline steels is aiming at achieving high strength and toughness. An experimental acicular ferrite (AF) ultralow carbon pipeline steel was investigated to correlate the Microstructural Characteristic of the steel to its strength and toughness behavior at the present work. The experimental result indicated that the AF ultralow carbon pipeline steel can well satisfy the high strength and toughness requirement. By comparing with the AF conventional carbon pipeline steel, the AF ultralow carbon pipeline steel possesses much higher additional toughness. In addition to having the conventional Microstructural Characteristics of the AF microstructure, the AF ultralow carbon pipeline steels were observed to present a layer of thin martensite film at the lath boundaries of the AF microstructure. Increasing in toughness of the AF ultralow carbon pipeline steel was analyzed to be related to the lath boundary thin films as well as its Microstructural Characteristics.

  • Microstructural Characteristic and toughening of an ultralow carbon acicular ferrite pipeline steel
    Acta Metallurgica Sinica, 2002
    Co-Authors: Ming-chun Zhao, Yiyin Shan, Furen Xiao, Ke Yang
    Abstract:

    The Microstructural Characteristic and its effect oil toughening of an ultralow carbon acicular ferrite pipeline steel were investigated by means of mechanical testing and Microstructural analysis. Experimental results showed that the acicular ferrite dominated microstructure can be obtained for the ultralow carbon pipeline steel through the clean melting and the optimized thermo-mechanical processing. It was also found that there exists a layer of thin martensite film at the grain boundary of ferrite. All these Microstructural Characteristics play important roles in enhancement of toughening for the ultralow carbon acicular ferrite pipeline steel.

Ming-chun Zhao - One of the best experts on this subject based on the ideXlab platform.

  • Lath boundary thin-film martensite in acicular ferrite ultralow carbon pipeline steels
    Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2005
    Co-Authors: Ming-chun Zhao, Toshihiro Hanamura, Hai Qiu, Ke Yang
    Abstract:

    Modern pipeline technology for the production of oil and gas pipeline steels is aiming at achieving high strength and toughness. An experimental acicular ferrite (AF) ultralow carbon pipeline steel was investigated to correlate the Microstructural Characteristic of the steel to its strength and toughness behavior at the present work. The experimental result indicated that the AF ultralow carbon pipeline steel can well satisfy the high strength and toughness requirement. By comparing with the AF conventional carbon pipeline steel, the AF ultralow carbon pipeline steel possesses much higher additional toughness. In addition to having the conventional Microstructural Characteristics of the AF microstructure, the AF ultralow carbon pipeline steels were observed to present a layer of thin martensite film at the lath boundaries of the AF microstructure. Increasing in toughness of the AF ultralow carbon pipeline steel was analyzed to be related to the lath boundary thin films as well as its Microstructural Characteristics.

  • Microstructural Characteristic and toughening of an ultralow carbon acicular ferrite pipeline steel
    Acta Metallurgica Sinica, 2002
    Co-Authors: Ming-chun Zhao, Yiyin Shan, Furen Xiao, Ke Yang
    Abstract:

    The Microstructural Characteristic and its effect oil toughening of an ultralow carbon acicular ferrite pipeline steel were investigated by means of mechanical testing and Microstructural analysis. Experimental results showed that the acicular ferrite dominated microstructure can be obtained for the ultralow carbon pipeline steel through the clean melting and the optimized thermo-mechanical processing. It was also found that there exists a layer of thin martensite film at the grain boundary of ferrite. All these Microstructural Characteristics play important roles in enhancement of toughening for the ultralow carbon acicular ferrite pipeline steel.

Andrea Bacigalupo - One of the best experts on this subject based on the ideXlab platform.

  • Second-order homogenization of periodic materials based on asymptotic approximation of the strain energy: formulation and validity limits
    Meccanica, 2014
    Co-Authors: Andrea Bacigalupo
    Abstract:

    In this paper a second-order homogenization approach for periodic material is derived from an appropriate representation of the down-scaling that correlates the micro-displacement field to the macro-displacement field and the macro-strain tensors involving unknown perturbation functions. These functions take into account of the effects of the heterogeneities and are obtained by the solution of properly defined recursive cell problems. Moreover, the perturbation functions and therefore the micro-displacement fields result to be sufficiently regular to guarantee the anti-periodicity of the traction on the periodic unit cell. A generalization of the macro-homogeneity condition is obtained through an asymptotic expansion of the mean strain energy at the micro-scale in terms of the Microstructural Characteristic size ɛ; the obtained overall elastic moduli result to be not affected by the choice of periodic cell. The coupling between the macro- and micro-stress tensor in the periodic cell is deduced from an application of the generalised macro-homogeneity condition applied to a representative portion of the heterogeneous material (cluster of periodic cell). The correlation between the proposed asymptotic homogenization approach and the computational second-order homogenization methods (which are based on the so called quadratic ansatze) is obtained through an approximation of the macro-displacement field based on a second-order Taylor expansion. The form of the overall elastic moduli obtained through the two homogenization approaches, here proposed, is analyzed and the differences are highlighted. An evaluation of the developed method in comparison with other recently proposed in literature is carried out in the example where a three-phase orthotropic material is considered. The Characteristic lengths of the second-order equivalent continuum are obtained by both the asymptotic and the computational procedures here analyzed. The reliability of the proposed approach is evaluated for the case of shear and extensional deformation of the considered two-dimensional infinite elastic medium subjected to periodic body forces; the results from the second-order model are compared with those of the heterogeneous continuum.

  • Second-order homogenization of periodic materials based on asymptotic approximation of the strain energy: formulation and validity limits
    arXiv: Materials Science, 2014
    Co-Authors: Andrea Bacigalupo
    Abstract:

    In this paper a second-order homogenization approach for periodic material is derived from an appropriate representation of the down-scaling that correlates the microdisplacement field to the macro-displacement field and the macro-strain tensors involving unknown perturbation functions. These functions take into account of the effects of the heterogeneities and are obtained by the solution of properly defined recursive cell problems. Moreover, the perturbation functions and therefore the micro-displacement fields result to be sufficiently regular to guarantee the anti-periodicity of the traction on the periodic unit cell. A generalization of the macro-homogeneity condition is obtained through an asymptotic expansion of the mean strain energy at the micro-scale in terms of the Microstructural Characteristic size e; the obtained overall elastic moduli result to be not affected by the choice of periodic cell. The coupling between the macro- and microstress tensor in the periodic cell is deduced from an application of the generalised macrohomogeneity condition applied to a representative portion of the heterogeneous material (cluster of periodic cell). The correlation between the proposed asymptotic homogenization approach and the computational second-order homogenization methods is obtained through an approximation of the macrodisplacement field based on a second-order Taylor expansion. The form of the overall elastic moduli obtained through the two homogenization approaches, here proposed, is analyzed and the differences are highlighted.

Toshihiro Hanamura - One of the best experts on this subject based on the ideXlab platform.

  • Lath boundary thin-film martensite in acicular ferrite ultralow carbon pipeline steels
    Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2005
    Co-Authors: Ming-chun Zhao, Toshihiro Hanamura, Hai Qiu, Ke Yang
    Abstract:

    Modern pipeline technology for the production of oil and gas pipeline steels is aiming at achieving high strength and toughness. An experimental acicular ferrite (AF) ultralow carbon pipeline steel was investigated to correlate the Microstructural Characteristic of the steel to its strength and toughness behavior at the present work. The experimental result indicated that the AF ultralow carbon pipeline steel can well satisfy the high strength and toughness requirement. By comparing with the AF conventional carbon pipeline steel, the AF ultralow carbon pipeline steel possesses much higher additional toughness. In addition to having the conventional Microstructural Characteristics of the AF microstructure, the AF ultralow carbon pipeline steels were observed to present a layer of thin martensite film at the lath boundaries of the AF microstructure. Increasing in toughness of the AF ultralow carbon pipeline steel was analyzed to be related to the lath boundary thin films as well as its Microstructural Characteristics.

Hai Qiu - One of the best experts on this subject based on the ideXlab platform.

  • Lath boundary thin-film martensite in acicular ferrite ultralow carbon pipeline steels
    Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2005
    Co-Authors: Ming-chun Zhao, Toshihiro Hanamura, Hai Qiu, Ke Yang
    Abstract:

    Modern pipeline technology for the production of oil and gas pipeline steels is aiming at achieving high strength and toughness. An experimental acicular ferrite (AF) ultralow carbon pipeline steel was investigated to correlate the Microstructural Characteristic of the steel to its strength and toughness behavior at the present work. The experimental result indicated that the AF ultralow carbon pipeline steel can well satisfy the high strength and toughness requirement. By comparing with the AF conventional carbon pipeline steel, the AF ultralow carbon pipeline steel possesses much higher additional toughness. In addition to having the conventional Microstructural Characteristics of the AF microstructure, the AF ultralow carbon pipeline steels were observed to present a layer of thin martensite film at the lath boundaries of the AF microstructure. Increasing in toughness of the AF ultralow carbon pipeline steel was analyzed to be related to the lath boundary thin films as well as its Microstructural Characteristics.