L. Lundin et al., REMANENT LIFE ASSESSMENT OF CREEP-RESISTANT MODIFIED 12-PERCENT CHROMIUM STEELS - MICROSTRUCTURAL ANALYSIS AND MICROSTRUCTURAL DEVELOPMENT MODELS, Scandinavian journal of metallurgy, 26(1), 1997, pp. 27-40
This paper presents the current status of the development work of 9-12
% chromium steels intended for use in the power generation industry. T
o meet the need for reliable remanent life assessment of these steels,
a co-operation between research groups specialised at microanalysis a
nd modelling of 9-12% chromium steels was initiated. The microstructur
e of several alloys was studied in detail using different methods of m
icroscopy and microanalysis including atom-probe field-ion microscopy,
TEM and AES. Concurrently, different kinetic models describing micros
tructural changes models were tested. It was shown that many microstru
ctural observations could be explained using thermodynamic and kinetic
models, e. g., the occurrence of Laves phase at the aging temperature
and the replacement of M7C3 by M23C6 during tempering. The currently
developed models can be used for predictions of the effects on microst
ructure of small changes in alloy composition and heat treatment. (C)
Munksgaard, 1997.