| Creep is the phenomenon that strain increases with the loading time when the load keeps constant. Creep damage of metallic materials after servicing for a long time will lead to failure, rupture even severe disaster, especially for the metals used in oil pipeline, nuclear power etc, so the study on creep behavior of the metals is very important.2205 dual-phase steel and 316 L steel are the steels often employed in oil pipeline, and the creep behavior of this two steels have been discussed in this article. The creep experiments of 2205 dual-phase steel and 316 L steel have been carried out at room temperature. Power law and logarithmic law can both well fit the creep deformation behavior of these stainless steels. The equations that describe the relation between creep strain ?, stress ? and time t have been confirmed for 2205 dual-phase steel and 316 L steel. The relaxation experiments of 2205 dual-phase steel and 316 L steel at room temperature have been carried out to verify the constitutive equations.The creep behavior of Inconel alloy 600 has been investigated with the applied stress between 450 and 650 MPa at 350?. The power law and logarithmic law have been used to fit the experimental data and to establish the constitutive equations during the creep process. It is found that the power law and logarithmic law can both describe the variation of creep strain with the time. However, the logarithmic law is superior to the power law due to its higher fidelity to the experimental data. In addition, we have analyzed the creep behavior of A508-3 steel with the temperature between 350? and 600??The common equations have been established based on the experimental data to describe the relation between the strain ?, stress ? and the time t. The creep activation energy Qc of A508-3 has been calculated, with the value between 72.999~88.269 KJ.mol-1. Also the equation between strain rate and the rupture time tr has been investigated according to the Monkman-Grant theory. |
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