Mechanical properties of ultra-high-strength steels at elevated temperatures

ABSTRACT

This paper presents an experimental study on the mechanical properties of ultra-high-strength steels at elevated temperatures. Tensile tests were carried out at 300–600°C on Docol 1200M and Docol 1400M steel samples. The results indicate that as the temperature increases Young’s Modulus, yield strength (YS) and ultimate tensile strength (UTS) display a decrease. YS/UTS ratios at 300°C are lower than those at room temperature, they make peaks at 400 and 500°C for Docol 1400M and Docol 1200M, respectively, and then decrease again beyond those temperatures. While total elongation continuously increases, uniform elongation slightly decreases with increasing temperature. Present carbides in tempered matrix continue to grow and new carbides are observed at the grain boundaries. Considering all roll forming parameters, 300°C seems the most convenient temperature for warm forming. In this sense, the warm roll forming has a potential for forming complex-shaped parts by reconciling strength with formability.

KEYWORDS:

• Ultra-high-strength steels
• martensitic steels
• roll forming
• warm forming

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Nuri Sen http://orcid.org/0000-0002-6501-5858

Gökhan Durucan http://orcid.org/0000-0002-6665-4547

Oktay Elkoca http://orcid.org/0000-0002-0007-0741

İlyas Uygur http://orcid.org/0000-0002-8744-5082

Additional information

Funding

The authors gratefully acknowledge the financial support provided by the Düzce University Research Fund (project no.: 2016.06.05.457).