Texture and mechanical properties of API X100 steel manufactured under various thermomechanical cycles

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Structural materials : properties, microstructure and processing, 2012, Vol.531, p.2-11
• Main Authors: Nafisi, S., Arafin, M.A., Collins, L., Szpunar, J.
• Format: Article
• Language: English
• Subjects: Anisotropy; API; Applied sciences; Bainite; Cross-disciplinary physics: materials science; rheology; EBSD; Elasticity. Plasticity; Exact sciences and technology; Ferrite; Finish rolling; Heat treatment; High strength low alloy steels; Materials science; Mechanical properties; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Other heat and thermomechanical treatments; Physics; Pipeline; Production techniques; Strength; Surface layer; Texture; Thermomechanical treatment; TMCP; Treatment of materials and its effects on microstructure and properties; X100
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2011.09.072

► Various thermomechanical cycles on texture and mechanical properties were studied. ► Steel that is rolled above the T nr was much more brittle than the other steels. ► The best results were achieved by finish rolling ends around the Ar3 temperature. The role of various finishing rolling operations on the texture and mechanical properties has been studied for API (American Petroleum Institute) X100 steel. It has been found that both the finish rolling start and end temperatures influence the final texture and thus, the mechanical properties and the anisotropy of these properties. High temperature finish rolling produces a very weak texture. This texture is a result of dynamic recrystallization, and associated with large grain size and inferior mechanical properties. A slightly delayed start of accelerated cooling led to the formation of large fraction of polygonal ferrite and increased the ductility at the expense of strength. Near-isothermal rolling in the range of 790–810 °C produced the highest texture intensities of both the desired {3 3 2}〈1 1 3〉 and the undesired {1 1 3}〈1 1 0〉 components. The latter texture components as well as the {1 0 0}〈1 1 0〉 component, mitigated the positive effect of the {3 3 2}〈1 1 3〉 component. On the other hand, a relatively higher finish rolling start temperature (840 °C) and a low finish rolling end temperature (700 °C) suppressed the strength of the {1 1 3}〈1 1 0〉 and {1 0 0}〈1 1 0〉 components, while the {3 3 2}〈1 1 3〉 component apparently was sufficient for the reduction of the anisotropy of mechanical properties. Partial deformation of the quasi-polygonal ferrites also appeared to have contributed to increasing the strength of the investigated steel.