Texture and yield strength anisotropy of microalloyed thermomechanically treated high-strength steels

Critical Assessment 16: Anisotropy in metals

“…45 In these circumstances, the strength anisotropy may reach levels up to *8%. 44 The sharpness of final textures and the associated anisotropy increase as the final rolling temperature is reduced in the austenite range and even further when the deformation continues after ferrite has started to form. 8 For strip steel, the anisotropy becomes greater with reduction in the coiling temperature after hot rolling.…”

“…In hot rolled steels, the yield stress and tensile strength are generally higher in the transverse direction than in the rolling direction and often show a minimum at *30u to the rolling direction. 44,45 Figure 8 shows results for a hot rolled steel microalloyed with niobium and vanadium, compared with modelled values based on Taylor theory. 45 Although the agreement is not perfect, it is sufficiently close to deduce that the anisotropy derives from crystallographic texture and not from microstructural banding as had been believed previously.…”

“…8 For strip steel, the anisotropy becomes greater with reduction in the coiling temperature after hot rolling. 44 It is now recognised that the toughness of steel plates often varies depending on the loading direction for reasons of texture as well as the microstructural effect described above. This has assumed considerable importance in steels for oil and gas pipelines, especially in arctic environments and regions susceptible to earthquakes.…”

Factors Affecting Texture Memory Appearing through α→γ→α Transformation in IF Steels

“…transformation in deep-drawable cold-rolled sheet steels. 1,2) On the other hand, it has been observed that the initial texture hardly changes in microalloyed low-carbon steels with a considerable amount of Mn such as 0.09 mass%C-0.62 mass%Mn-0.03 mass%Nb, 3) 0.1 mass%C-1.35 mass%Mn-0.03 mass%Nb 4) and 0.19 mass%C-1.35 mass% Mn-0.06 mass%Nb 5) controlled-rolled sheet steels, in which martensitic transformation took place during cooling. In these studies, the mechanism was not discussed.…”

Influence of directionality on strength and impact behaviour of high strength steels

“…The major components of the texture of the pancaked austenite are {110}n112m and {112} n111m, and these give rise to the {332}n113m and {113}n110m components of the transformed ferrite respectively. 21 It is generally accepted that as the texture develops, so does the anisotropy of the yield strength, i.e. increase in transverse strength over longitudinal.…”