Effect of Delta Ferrite on Microstructure and Mechanical Properties of High-Chromium Martensitic Steel

Journal Article · Fri Feb 15 00:00:00 EST 2019 · Journal of Materials Engineering and Performance

DOI:https://doi.org/10.1007/S11665-019-3862-8· OSTI ID:22970946

Chakraborty, Gopa; Ganesh Kumar, J.; Vasantharaja, P.; Das, C. R.; Albert, S. K.; Laha, K. ^[1]

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1. Indira Gandhi Centre for Atomic Research, Metallurgy and Materials Group (India)

The fusion zone of modified 9Cr-1Mo steel experiencing a peak temperature of 1450 °C and varying cooling rates between 1 and 40 °C/s from the peak temperature is simulated using Gleeble thermal simulator. Mechanical properties of the simulated samples are assessed by ball indentation and impression creep tests. The study evaluates the effect of cooling rate on volume fraction, morphology of retained delta ferrite in the simulated partially melted zone of an autogenous weld, and subsequently its effect on the mechanical properties of this zone. With varying cooling rate, volume fraction of delta ferrite does not change much; however, its morphology changes from polygonal island to grain boundary network in case of excessive slow cooling (1 °C/s). Morphological variation of delta ferrite affects the creep properties of this zone. Partially melted zone, which is cooled at 1 °C/s with delta ferrite present in the interdendritic regions, exhibits maximum creep strain and creep strain rate.

• OSTI ID: 22970946
• Journal Information: Journal of Materials Engineering and Performance, Vol. 28, Issue 2; Conference: 2017 Materials Science and Technology Conference, Pittsburgh, PA (United States), 8-12 Oct 2017; Other Information: Copyright (c) 2019 ASM International; Country of input: International Atomic Energy Agency (IAEA); ISSN 1059-9495
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COOLING
CREEP
FERRITES
GRAIN BOUNDARIES
MARTENSITIC STEELS
MORPHOLOGY
SIMULATION
STRAIN RATE
ZONES