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Title: Microstructure of welded and weld-simulated modified 9Cr-1Mo (P 91) ferritic steel

Book ·
OSTI ID:442943
;  [1];  [2]
  1. Graz Univ. of Technology (Austria)
  2. Oak Ridge National Lab., TN (United States)

Within the last 30 years significant advances in materials development have been made which have enhanced the operation temperature of thermal power plants led to an improvement in efficiency. Currently, a great deal of work relating to the modified 9% Cr-1/5 Mo steel (P 91) is in progress. This type of steel was originally considered to be an appropriate candidate for Fast Breeder Applications, and it was designed by Oak Ridge National Laboratory. Up to the present, several modifications of 9% chromium steels have been developed in several labs all over the globe containing different portions of tungsten and molybdenum. This report focuses on the microstructural characterization of a heavy section multi pass weld done on a tube composed of P 91 steel. Weld simulations, using the Gleeble 1500 technology, were successfully applied to aid the microstructural study of the heat affected zone (HAZ). As revealed by the investigations, post weld heat treatment (PWHT) results in a softening of the heat affected zone in an area close to the uninfluenced base metal. According to the observed microstructure and Gleeble simulations, the peak temperature of the soft zone during welding falls within a temperature range between A{sub C1} (= 810 C) and slightly above A{sub C3} typically 900--930 C which was discovered for the first time in a previous investigation.

DOE Contract Number:
AC05-84OR21400
OSTI ID:
442943
Report Number(s):
CONF-950682-; ISBN 0-87170-567-2; TRN: IM9712%%368
Resource Relation:
Conference: 4. international conference on trends in welding research, Gatlinburg, TN (United States), 5-9 Jun 1995; Other Information: PBD: 1996; Related Information: Is Part Of Trends in welding research: Proceedings of the 4. international conference; Smartt, H.B.; Johnson, J.A. [eds.] [Idaho National Engineering Lab., Idaho Falls, ID (United States)]; David, S.A. [ed.] [Oak Ridge National Lab., TN (United States)]; PB: 836 p.
Country of Publication:
United States
Language:
English