17,075 research outputs found
The development of creep damage constitutive equations for low Cr-Mo alloy steel and its weldment at low stress
The ultimate objective of this research project is to develop creep damage constitutive equations for low Cr-Mo alloy and its weldment under low stress (0.2-0.4 yield stress,Ï_Y). This paper summarizes a critical analysis on the cavity nucleation and growth and the deformation mechanisms and creep damage evolution characteristics at low stress with temperature ranging from 450 °C to 650 °C, in order to firmly establish the physical base for the theoretical constitutive modeling work. Moreover, it covers the influence of the stress level on the development of cavity nucleation and growth, leading to the final rupture, and proposes and discusses a new idea for failure criterion to be used in the constitutive equations under uni-axial stress state. This paper contributes to knowledge and the development of methodology
Review of creep deformation and rupture mechanism of P91 alloy for the development of creep damage constitutive equations under low stress level
This paper presents a review of creep deformation and rupture mechanism of P91 alloy for the development of its creep damage constitutive equations under lower stress level. Creep damage is one of the serious problems for the high temperature industries and computational approach (such as continuum damage mechanics) has been developed and used, complementary to the experimental approach, to assist safe operation. However, there are no ready creep damage constitutive equations to be used for prediction the lifetime for this type of alloy, partially under low stress.
The paper reports a critical review on the deformation and damage evolution characteristics of this alloy, particularly under low stress, to form the physical base for the development of creep damage constitutive equations. It covers the influence of the stress level, states of stress, and the failure criterion
Preliminary analysing of experimental data for the development of high Cr Alloy Creep damage Constitutive Equations
This conference paper presents the current research of preliminary analysing of experimental data for the development of high Cr Alloy Creep damage Constitutive Equations (such as P91 alloy). Firstly, it briefly introduces the background of general creep deformation, rupture and continuum damage mechanics. Secondly, it illustrates the constitutive equations used for P91 alloy or its weldment, especially of the form and deficiencies of two kinds of most widely used typical creep damage constitutive equations Kachanov-Rabotnov-Hayhurst (KRH) and Xuâs formations. And then, the methodology for development of new set constitutive equation proposed by Xu (2004) has been followed in this research. Fourthly, there is a critically analysis of the specific experiment data for P91 alloy and its weldment. Afterwards, the specific requirements for developing a new set constitutive equation have been reported
Analyzing the characteristics of the cavity nucleation, growth and coalescence mechanism of 9Cr-1Mo-VNb steel (P91) steel
Creep damage is one of the serious problems for the high temperature industries and computational approach (such as continuum damage mechanics) has been developed and used, complementary to the experimental approach, to assist safe operation. However, there are no ready creep damage constitutive equations to be used for predicting the lifetime for this type of alloy, particularly for low stress. This paper presents an analysis of the cavity nucleation, growth and coalescence mechanism of 9Cr-1Mo-VNb steel (P91 type) under high and low stress levels and multi-axial stress state
Review on the current state of developing of advanced Creep Damage Constitutive Equations for high Chromium Alloy
This paper presents a review of developing of creep damage constitutive equations for high chromium alloy (such as P91 alloy). Firstly, it briefly introduces the background of creep damage for P91 materials. Then, it summarizes the typical creep damage constitutive equations developed and applied for P91 alloy, and the main deficiencies of KRH (Kachanov-Robatnov-Hayhurst) type and Xus type constitutive equations. Finally it suggests the directions for future work. This paper contributes to the knowledge for the developing creep damage constitutive equations for the specific material
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