Experimental study on creep-fatigue behaviors of chinese P92 steel with consideration of several important factors

Cyclic deformation and damage mechanisms of 9%Cr steel under hybrid stress-strain controlled creep fatigue interaction loadings

Creep-fatigue interaction and damage behavior in 9-12%Cr steel under stress-controlled cycling at elevated temperature: Effects of holding time and loading rate

A universal constitutive model for hybrid stress-strain controlled creep-fatigue deformation

Thermomechanical fatigue (TMF) loading is inevitable during the operation of ultra-supercritical power plants. In the present work, TMF tests are carried out at strain rates of 5 × 10−5/s to 4 × 10−4/s and in-phase (IP) and out-of-phase (OP) to investigate the cyclic deformation and damage mechanisms of P92 steel. The results reveal that the increase in strain rate leads to a significant improvement in fatigue life under both IP-TMF and OP-TMF, in which OP-TMF induces more severe damage to fatigue life than IP-TMF. It was found that the fatigue life reaches a maximum after a strain rate of 1 × 10−4 s−1. It is important to note that the action of dynamic strain ageing (DSA) is strain rate-, fatigue cycle- and phase angle-dependent. It was also demonstrated that the effect of the strain rate on the fatigue life is a combined effect of DSA, fatigue cracks, creep voids and oxidation. Additionally, the predictive abilities of various traditional life prediction methods under various loading conditions are comparatively assessed.

Thermomechanical fatigue behaviour and damage mechanisms in a 9% Cr steel: Effect of strain rate


 This paper studies the multi-axial creep behavior of Inconel 718 alloy at 700 °C. The stress triaxiality was introduced into the sample by adding U-shaped notches of various sizes and shapes. Furthermore, the multi-axial creep test of notched round bar was completed, and the sample slice after the creep test was subjected to scanning electron microscopy (SEM) microscopic examination. The influence of notch radius on its creep behavior and damage evolution was studied through experimental and numerical investigation. The finite element method (FEM) implemented by Gurson–Tvergaard–Needleman (GTN) model is used to simulate the evolution of damage in multi-axial stress state. With the comparison between experimental and numerical data, the multi-axial creep behaviors are clearly revealed in terms of stress triaxiality, creep strain (stress), void volume fraction (VVF), and so on. It was found that the great agreement is achieved between FEM and test data, and multi-axial creep behavior is well predicted.

The Studies on Multiaxial Creep Behavior of Inconel 718 Notched Bar at 700 °C

A novel diffusion barrier of electrodeposited CoWP layer between copper and silicon: Preparation and Performance

In this paper, tensile test and creep-fatigue test at 650°C were carried out for 316L steel with and without prior thermal aging. The effect of aging on creep-fatigue interaction of 316L steel is analyzed in detail. Microscopic observations are performed on fatigue and creep-fatigue specimens to study the microstructure characteristics affected by aging, creep, and fatigue. Actually, three strain amplitude loadings of ±0.3%, ±0.4%, and ±0.5% are adopted in creep-fatigue tests. The creep-fatigue behaviors of unaged and aged 316L steel are investigated in depth for varying strain amplitude. The creep-fatigue constitutive model is constructed by using Chaboche mixed softening and hardening model combined with strain hardening creep. Life prediction models are compared and used to do prediction. The applicability of different models is recommended. The accuracy of the models is analyzed by comparing with the test data. The agreement is achieved between theoretical and experimental predictions. 

Fengping Zhong

Papers

Experimental study on creep-fatigue behaviors of chinese P92 steel with consideration of several important factors

The Studies on Multiaxial Creep Behavior of Inconel 718 Notched Bar at 700 °C

A novel diffusion barrier of electrodeposited CoWP layer between copper and silicon: Preparation and Performance

Experimental and theoretical research on creep‐fatigue behaviors of 316L steel with and without 650°C thermal aging

Experimental and numerical study on multiaxial creep behavior of 16MND5 steel at 700