Modeling for fracture in materials under long-term static creep loading and neutron irradiation. Part 3. Crack growth rate prediction for austenitic materials

Abstract

We propose an engineering method which permits predicting the creep crack growth rate under neutron irradiation conditions. Theoretical analysis of the creep crack-tip stress-strain state is carried out. Calculations are performed to determine the effect of neutron flux intensity (flux) and pre-irradiation dose (fluence) on the crack growth rate.

Methods of Computational Determination of Growth Rates of Fatigue, Creep, and Thermal Fatigue Cracks in Poly- and Monocrystalline Blades of Gas Turbine Units

“…Its advantage over C t ( ) is that it can be directly found by experiments. In some cases, one can avoid computation of the cumbersome integrals (14) and calculate C * by simplified relations based on computation of SIF and reference stresses [17][18][19] (for the plne-strain state):…”

A method for predicting fracture resistance of material in cyclic loading under viscoelastoplastic deformation and neutron irradiation conditions

“…The structure operation time is, for example, 2 10 5 ⋅ h. The inelastic strain range in cycles is the same. Based on [14][15][16], we have ε ε…”

“…This relation can be derived using stress rupture ductility data for a material irradiated with a neutron flux Φ and pre-irradiated with neutron fluence F [14][15][16]. Figure 2 shows schematically the dependence of creep rupture strength σ and stress rupture ductility ε f on time to failure t f together with the transgranular and intergranular fracture regions.…”

“…can be determined from the functions ε f f t ( ) derived by means of a physical-mechanical model of intergranular fracture [14][15][16]. Consider prediction of fatigue curves by the Coffin-Manson equation [12,13]:…”

“…h −1 ) [21]. Let us assess ξ * by using the proposed method and data provided in [14][15][16]. Figure 8 shows the calculated ε ξ f ( ) function at T =°600 C for steels of Kh18N9 and Kh18N10T grades in the initial state (Φ = 0).…”