Mechanical anisotropy in Ca-treated and ultra-low sulphur HSLA-100 steel

Abstract

A few elongated MnS inclusions were observed in ultra-low sulphur HSLA-100 steel which significantly decreased the yield strength (YS), ultimate tensile strength and notch toughness of short transverse direction. The slight anisotropies of YS (≈5 MPa) and notch toughness (≈15 J) between longitudinal and transverse directions are correlated to the presence of texture components in the vicinity of {113}<110> and {554}<225>. In the case of anisotropy between longitudinal and short transverse directions, it is found that recognising the contribution of each effective factor in the creation of strength anisotropy is not possible. However, the most primary effective factor in the creation of remarkable notch toughness anisotropy (≈70 Pct), especially at −85°C, is related to the existence of elongated MnS inclusions.

Growth Behavior of MnS on CaO–MgO–Al₂O₃ Oxide in Al-killed Ca-treated Resulfurized Steel

“…1) The morphologies and distribution of MnS inclusions have an obvious influence on the mechanical properties of steel. [2][3][4] It is beneficial for isotropy of mechanical properties to obtain more spherical or spindle-shaped and evenly distributed MnS inclusions in steel. [5][6][7] By using appropriate oxides as heterogeneous nucleation cores to improve the morphologies and distribution of MnS inclusions is a useful method, which is also a research hotspot at present.…”

Effect of spherical inclusions on fatigue anisotropy of HSLA-100 steel

“…Anisotropy of mechanical properties, especially fatigue anisotropy in such large-scale welded constructions, is of considerable importance [2][3][4]. Although in the past decades, a considerable number of investigations have been carried out on the HSLA-100 steel [5][6][7][8]; however, the fatigue anisotropy of HSLA-100 steel has not been explored yet.…”