The Creep Behaviour of 310-Type Stainless Steel

Abstract

Abstract The primary and steady-state creep behaviour of 310-type stainless steel has been investigated over the temperature range 500–700°C (0.46–0.58 Tm ). The steady-state stress exponent, n, increased slightly with increasing grain size, d, from n= 5.9 at d = 40 μm to n = 6.4 at d = 100 μm at a test temperature T = 600°C. The activation energy for steady-state creep, Q c, determined at σ = 300 MPa was 250±6.4 kJ mol−1 for d = 40 μm. This value of Q c is approximately equal to that for the volume self-diffusion of iron (280 kJ mol−1). The activation energy determined for primary creep is almost the same as that for secondary creep. The grain diameter parameter, m, in the equation ec = Aσn d m exp (− Q c/RT) was determined to be –1.67 for σ = 300 MPa and T = 600°C. This value is slightly different from a previously published value of m= −2, which was obtained at a lower applied stress. Using the strain-time data obtained in these tests, constitutive equations have been developed to describe both the pri...