Elevated temperature compressive steady state deformation and failure in the oxide dispersion strengthened alloy MA 6000E

A study of the compressive flow strength-strain rate behavior of the oxide dispersion strengthened (ODS) alloy MA 6000E has been conducted between 1144 and 1366 K. Specimens taken in the longitudinal, long transverse, and short transverse bar directions were tested at strain rates ranging from 2.1 × 10⁻⁵ s⁻¹ to 2.1 × 10⁻⁷ s⁻¹. The inherent compressive strength of MA 6000E was essentially independent of orientation. Testing at the higher temperatures and slower strain rates produced large scale cracking. Such cracks formed and propagated in bands in which slip had dissolved and redistributed the γ’ precipitates. Steady state deformation could be described through use of a threshold stress model of creep where threshold stresses were calculated as functions of temperature and orientation from the relatively fast flow stress-strain rate data and the assumption that the effective stress exponent was 3.5.