Effect of oxidation on creep data: Part 1 -Comparison between some constant load creep results in air and vacuum on 2 1/4Cr-1Mo steel from 600 to 700 deg C

摘要

A description is given of two chambers specially developed for creep testing in controlled environment which accommodate inside them the complete load train, with the extensometry system and thermocouples. The creep machines used in this project present the advantage of allowing performance of both constant load or constant stress testing, using interchangeable profile cams. A set of preliminary creep results on 2 1/4Cr-1Mo was obtained at 600, 650 and 700 deg C at four stress levels in each case, under constant load, in air and vacuum. The data were examined according to the conventional methodology of creep data analysis by the identification of parameters from the Norton, Arrhenius and Monkman-Grant relations and the application of some parameterization techniques as a first attempt to establish a systematic comparison between creep properties in air and vacuum in this steel.