Microstructure and properties of thermomechanically strengthened reinforcement bars: A comparative assessment of plain-carbon and low-alloy steel grades

Journal Article · Sun Jun 01 04:00:00 EDT 1997 · Journal of Materials Engineering and Performance

DOI:https://doi.org/10.1007/s11665-997-0098-9· OSTI ID:514701

Ray, A; Mukerjee, D; Sen, S K; Bhattacharya, A; Dhua, S K; Prasad, M S; Banerjee, N; Popli, A M ^[1]; Sahu, A K ^[2]

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1. Steel Authority of India Ltd., Ranchi (India). Research and Development Centre for Iron and Steel
2. Steel Authority of India Ltd., West Bengal (India). Durgapur Steel Plant

An extensive investigation has been carried out to study structure-property characteristics and corrosion behavior in three varieties of thermomechanically treated (TMT) reinforcement bars (rebars) produced in an integrated steel plant under the Steel Authority of India Limited. Three experimental steel heats--one of plain-carbon and two of low-alloy chemistry--were chosen for the study. Of the two low-alloy heats, one was copper-bearing and the other contained both copper and chromium for improved corrosion resistance. Hot-rolled bars for each specific chemistry were subjected to in-line thermomechanical treatment, where quenching parameters were altered to achieve different yield strength levels. All the TMT rebars, regardless of chemistry and strength level, exhibited a composite microstructure consisting of ferrite-pearlite at the core and tempered martensite at the rim. Although a tendency toward formation of Widmanstaetten ferrite was evident in bars of 500 and 550 MPa yield strength levels, no adverse effect on their strength and ductility was observed. From the standpoint of mechanical properties, the rebars not only conformed to minimum yield strength requirements, but also exhibited high elongation values (21 to 28%) and excellent bendability. Corrosion studies of both TMT and cold-twisted and deformed (CTD) rebars subjected to different laboratory tests indicated that corrosion resistance increased in this order: CTD, plain-carbon TMT, copper-bearing TMT, and copper/chromium-bearing TMT.

• Sponsoring Organization: USDOE
• OSTI ID: 514701
• Journal Information: Journal of Materials Engineering and Performance, Journal Name: Journal of Materials Engineering and Performance Journal Issue: 3 Vol. 6; ISSN 1059-9495; ISSN JMEPEG
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CARBON STEELS
CHROMIUM
COPPER
CORROSION RESISTANCE
DUCTILITY
ELONGATION
LOW ALLOY STEELS
MECHANICAL PROPERTIES
MICROSTRUCTURE
REINFORCED CONCRETE
THERMOMECHANICAL TREATMENTS
YIELD STRENGTH