The Experts below are selected from a list of 2493972 Experts worldwide ranked by ideXlab platform

Guo-dong Wang - One of the best experts on this subject based on the ideXlab platform.

  • study on microstructure of low Carbon 12 chromium stainless steel in high temperature heat affected zone
    Materials & Design, 2010
    Co-Authors: Huaibei Zheng, Laizhu Jiang, Baosen Wang, Zhen-yu Liu, Guo-dong Wang
    Abstract:

    Coarsening, embrittlement and corrosion sensitization in high temperature heat-affected zone (HTHAZ) are the major problems when low Carbon 12% chromium stainless steel is being welded, which induce deterioration of the impact toughness at low temperature and intergranular corrosion resistance. This study investigated the corresponding microstructures in HTHAZ with different chemical compositions and heat inputs through thermal simulation tests. There are several primary conclusions: (1) When ferrite factor (FF) is above 9.0, the microstructure in HTHAZ is fully ferrite or a small amount of martensite net likely distributing along delta ferrite grain boundaries. On the other hand, if FF is below 9.0, the martensite content increases with the decreasing of FF. (2) Heat input influences the microstructure of high FF steel in HTHAZ. The martensite content and its distribution of low FF steel are not sensitive to heat inputs, but the grain size grows up with the increase of heat inputs. (3) The coarse Ti-rich particles in low FF steels containing Ti can promote intragranular austenite formation inside delta ferrite resulting in packet morphology of martensite. On the other hand, martensite of low FF steels only stabilized with Nb is characterized by grain boundary allotriomorphs, Widmanstatten structures and secondary sawteeth. This martensite reticularly distributes along ferrite grain boundaries.

  • Study on microstructure of low Carbon 12% chromium stainless steel in high temperature heat-affected zone
    Materials & Design, 2010
    Co-Authors: Huaibei Zheng, Laizhu Jiang, Baosen Wang, Zhen-yu Liu, Guo-dong Wang
    Abstract:

    Coarsening, embrittlement and corrosion sensitization in high temperature heat-affected zone (HTHAZ) are the major problems when low Carbon 12% chromium stainless steel is being welded, which induce deterioration of the impact toughness at low temperature and intergranular corrosion resistance. This study investigated the corresponding microstructures in HTHAZ with different chemical compositions and heat inputs through thermal simulation tests. There are several primary conclusions: (1) When ferrite factor (FF) is above 9.0, the microstructure in HTHAZ is fully ferrite or a small amount of martensite net likely distributing along delta ferrite grain boundaries. On the other hand, if FF is below 9.0, the martensite content increases with the decreasing of FF. (2) Heat input influences the microstructure of high FF steel in HTHAZ. The martensite content and its distribution of low FF steel are not sensitive to heat inputs, but the grain size grows up with the increase of heat inputs. (3) The coarse Ti-rich particles in low FF steels containing Ti can promote intragranular austenite formation inside delta ferrite resulting in packet morphology of martensite. On the other hand, martensite of low FF steels only stabilized with Nb is characterized by grain boundary allotriomorphs, Widmanstatten structures and secondary sawteeth. This martensite reticularly distributes along ferrite grain boundaries.

Huaibei Zheng - One of the best experts on this subject based on the ideXlab platform.

  • study on microstructure of low Carbon 12 chromium stainless steel in high temperature heat affected zone
    Materials & Design, 2010
    Co-Authors: Huaibei Zheng, Laizhu Jiang, Baosen Wang, Zhen-yu Liu, Guo-dong Wang
    Abstract:

    Coarsening, embrittlement and corrosion sensitization in high temperature heat-affected zone (HTHAZ) are the major problems when low Carbon 12% chromium stainless steel is being welded, which induce deterioration of the impact toughness at low temperature and intergranular corrosion resistance. This study investigated the corresponding microstructures in HTHAZ with different chemical compositions and heat inputs through thermal simulation tests. There are several primary conclusions: (1) When ferrite factor (FF) is above 9.0, the microstructure in HTHAZ is fully ferrite or a small amount of martensite net likely distributing along delta ferrite grain boundaries. On the other hand, if FF is below 9.0, the martensite content increases with the decreasing of FF. (2) Heat input influences the microstructure of high FF steel in HTHAZ. The martensite content and its distribution of low FF steel are not sensitive to heat inputs, but the grain size grows up with the increase of heat inputs. (3) The coarse Ti-rich particles in low FF steels containing Ti can promote intragranular austenite formation inside delta ferrite resulting in packet morphology of martensite. On the other hand, martensite of low FF steels only stabilized with Nb is characterized by grain boundary allotriomorphs, Widmanstatten structures and secondary sawteeth. This martensite reticularly distributes along ferrite grain boundaries.

  • Study on microstructure of low Carbon 12% chromium stainless steel in high temperature heat-affected zone
    Materials & Design, 2010
    Co-Authors: Huaibei Zheng, Laizhu Jiang, Baosen Wang, Zhen-yu Liu, Guo-dong Wang
    Abstract:

    Coarsening, embrittlement and corrosion sensitization in high temperature heat-affected zone (HTHAZ) are the major problems when low Carbon 12% chromium stainless steel is being welded, which induce deterioration of the impact toughness at low temperature and intergranular corrosion resistance. This study investigated the corresponding microstructures in HTHAZ with different chemical compositions and heat inputs through thermal simulation tests. There are several primary conclusions: (1) When ferrite factor (FF) is above 9.0, the microstructure in HTHAZ is fully ferrite or a small amount of martensite net likely distributing along delta ferrite grain boundaries. On the other hand, if FF is below 9.0, the martensite content increases with the decreasing of FF. (2) Heat input influences the microstructure of high FF steel in HTHAZ. The martensite content and its distribution of low FF steel are not sensitive to heat inputs, but the grain size grows up with the increase of heat inputs. (3) The coarse Ti-rich particles in low FF steels containing Ti can promote intragranular austenite formation inside delta ferrite resulting in packet morphology of martensite. On the other hand, martensite of low FF steels only stabilized with Nb is characterized by grain boundary allotriomorphs, Widmanstatten structures and secondary sawteeth. This martensite reticularly distributes along ferrite grain boundaries.

J.i. Rawlinson - One of the best experts on this subject based on the ideXlab platform.

  • Electromagnetic transition rates of Carbon-12 and Oxygen-16 in rotational-vibrational models
    Physical Review C, 2020
    Co-Authors: C. J. Halcrow, J.i. Rawlinson
    Abstract:

    We develop a formalism to calculate electromagnetic (EM) transition rates for rotational-vibrational models of nuclei. The formalism is applied to recently proposed models of Carbon-12 and Oxygen-16 which are inspired by nuclear dynamics in the Skyrme model. We compare the results to experimental data, as well as other nuclear models. The results for Carbon-12 are in good agreement with the data across all models, making it difficult to differentiate the models. More experimental data is needed to do this, and we suggest which transitions would be most interesting to measure. The models of Oxygen-16 are less successful in describing the data, and we suggest some possible improvements to our approximations which may help.

  • An alpha particle model for Carbon-12
    Nuclear Physics A, 2018
    Co-Authors: J.i. Rawlinson
    Abstract:

    Abstract We introduce a new model for the Carbon-12 nucleus and compute its lowest energy levels. Our model is inspired by previous work on the rigid body approximation in the B = 12 sector of the Skyrme model. We go beyond this approximation and treat the nucleus as a deformable body, finding several new states. A restricted set of deformations is considered, leading to a configuration space C which has a graph-like structure. We use ideas from quantum graph theory in order to make sense of quantum mechanics on C even though it is not a manifold. This is a new approach to Skyrmion quantisation and the method presented in this paper could be applied to a variety of other problems.

Martin Freer - One of the best experts on this subject based on the ideXlab platform.

Ulfg Meisner - One of the best experts on this subject based on the ideXlab platform.

  • ab initio calculation of the hoyle state
    Physical Review Letters, 2011
    Co-Authors: Evgeny Epelbaum, H Krebs, Ulfg Meisner
    Abstract:

    The Hoyle state plays a crucial role in the helium burning of stars heavier than our Sun and in the production of Carbon and other elements necessary for life. This excited state of the Carbon-12 nucleus was postulated by Hoyle as a necessary ingredient for the fusion of three alpha particles to produce Carbon at stellar temperatures. Although the Hoyle state was seen experimentally more than a half century ago nuclear theorists have not yet uncovered the nature of this state from first principles. In this Letter we report the first ab initio calculation of the low-lying states of Carbon-12 using supercomputer lattice simulations and a theoretical framework known as effective field theory. In addition to the ground state and excited spin-2 state, we find a resonance at -85(3) MeV with all of the properties of the Hoyle state and in agreement with the experimentally observed energy.