Title: Development of microstructure and creep resistance of a martensitic creep resistant steel

Authors: Borut Žužek; Bojan Podgornik; Fevzi Kafexhiu

Addresses: Institute of Metals and Technology, Lepi pot 11, 1000 Ljubljana, Slovenia ' Institute of Metals and Technology, Lepi pot 11, 1000 Ljubljana, Slovenia ' Institute of Metals and Technology, Lepi pot 11, 1000 Ljubljana, Slovenia

Abstract: In thermal power stations, 9-12 % Cr steels are widely used for components operating at elevated temperatures. In the present work, the influence of quenching and tempering temperatures on microstructure evolution of 9-12 % Cr creep resistant steels was studied. It was found that quenching and tempering parameters influence the number, size, and mutual spacing of precipitates in the steel. The effect of different heat treatment parameters on the steady-state creep rate and time to rupture showed that for the higher quenching temperature, the number of precipitates increases while their mutual spacing decreases, which leads to improved creep resistance. Effect of tempering temperatures is not so pronounced as in the case of quenching temperature.

Keywords: austenitising; tempering; creep resistance; mechanical properties; precipitates.

DOI: 10.1504/IJMMP.2017.091118

International Journal of Microstructure and Materials Properties, 2017 Vol.12 No.3/4, pp.301 - 309

Received: 23 Jan 2017
Accepted: 14 Dec 2017

Published online: 04 Apr 2018 *

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