Development Of Cold Rolling Texture Research Articles

Unique effect of carbon addition on development of deformation texture through changes in slip activation and twin deformation in heavily cold-rolled Fe-3% Si alloys

The effect of carbon addition on the development of cold-rolling texture in heavily cold-rolled ultra-low carbon (ULC) 3% Si steel (<0.0005 mass% C-3.11 mass% Si) and low carbon (LC) 3% Si steel (0.016 mass% C-3.10 mass% Si) was investigated experimentally and theoretically. A higher carbon content in LC 3% Si steel led to the development of a {100}<011> cold-rolling texture compared with ULC 3% Si steel when the rolling reduction was 90%, which was the opposite tendency to that for conventional carbon steel without silicon content. According to slip bands observations at early stages of plastic deformation, carbon addition activated pencil-glide slip deformation on {110}, {112} and {123} slip planes and promoted deformation twinning, while only {110}<111> slip deformation was observed in ULC 3% Si steel. Crystal plasticity simulation implied that the combined effect of pencil-glide slips and twinning contributes significantly to the development of the {100}<011> cold-rolling texture in heavily cold-rolled LC 3% Si steel.

Role of hard martensite phase prior to cold-rolling on microstructure evolution after annealing in ferritic stainless steel

To improve the surface quality of 16mass%Cr ferritic stainless steel sheets processed by cold-rolling and subsequent annealing, the role of the hard martensite phase, in particular, the hardness ratio k between martensite and ferrite prior to cold-rolling on microstructure evolution was investigated by varying the k value through tempering specimens at different temperatures after intercritical annealing. In the specimen with the high ratio k (k>2.0), the heterogeneous deformation in ferrite around the hard martensite becomes prominent and the areas with the high KAM value are locally limited with less development of cold-rolling texture. The specimen with the small ratio k (k<2.0), however, shows rather uniform deformation structure, because tempered martensite deforms easily. Therefore, the recrystallized grain with the specimen k>2.0 becomes fine, because the presence of hard martensite provides the nucleation site of recrystallization leading to fragmenting the elongated {100}<011>colony structure, and the orientation is randomized. Consequently, the presence of the hard martensite phase prior to cold-rolling is effective for preventing the ridging of ferritic stainless steel sheets.

Anisotropy of Young's modulus and tensile properties in cold rolled α′ martensite Ti–V–Sn alloys

Young's modulus and tensile properties of cold rolled Ti–8 mass% V and (Ti–8 mass% V)–4 mass% Sn alloy plates consisting of α′ martensite were investigated as a function of tensile axis orientation in this work. A single phase of α′ (hcp) martensite is obtained in Ti–8 mass% V and (Ti–8 mass% V)–4 mass% Sn alloys by quenching after solution treatment. By 86% cold rolling, acicular α′ martensite microstructures change into extremely refined dislocation cell-like structure with an average size of 60 nm, accompanied with the development of cold rolling texture in which the basal plane normal is tilted from the plate normal direction (ND) toward transverse direction (TD) at angles of ±49° for Ti–8% V alloy and ±46° for (Ti–8 mass% V)–4 mass% Sn alloy. No apparent anisotropy of Young's modulus ( E) is observed for as-quenched Ti–8% V ( E = 76–83 GPa) and (Ti–8% V)-4%Sn ( E = 69–79 GPa). In contrast, Young's modulus increases with increasing angle from the rolling direction (RD) to TD for cold rolled Ti–8% V ( E = 72–94 GPa) and (Ti–8% V)–4%Sn ( E = 63–85 GPa). The observed anisotropy of Young's modulus can be reasonably explained in terms of the cold rolling α′ texture. 0.2% proof stress and tensile strength are independent of tensile orientation for cold rolled Ti–8% V and (Ti–8% V)–4%Sn alloys. In contrast, larger elongation to fracture is obtained in specimens deviated by 30°, 45° and 60° from RD than by 0°, 75° and 90°. Scanning electron microscopy (SEM) fractographs reveal that quasi-cleavage-like fracture plane appears in 0° specimen of cold rolled Ti–8% V which shows brittle fracture and other specimens of cold rolled Ti–8% V and (Ti–8% V)–4%Sn alloys are fractured accompanied with necking and dimple formation. It is suggested from these results that brittle fracture is related to the activation of limited number of slip system and Sn addition leads to the activation of multiple slip systems.

集合組織研究の現状と課題―Ｔａｙｌｏｒモデルの問題点と限界―

Recent trends in the field of texture investigations are briefly reviewed. ODF and EBSP analyses have made most significant contribution to the progress in the texture investigations. Owing to the development of these two experimental techniques, we can now not only quantitatively evaluate textures of various materials, but also we can directly correlate the distribution of main texture components with the observed microstructures. As to the theoretical investigations, the development of rolling textures of various metals has been intensively studied by using Taylor's model. In this paper, the validity of the basic assumption of the homogeneous deformation adopted in this model is critically examined in detail. All metallographic observations made on cold rolled pure Fe and Al do not support this assumption. It is strongly suggested that dislocation substructures developed during cold rolling strongly affect the development of cold rolling textures.

Rolling texture in the intermetallic compound Ni76Al24(B)

The development of cold rolling texture in the intermetallic compound Ni3Al(B) has been investigated as a function of rolling reduction, using the conventional pole figure as well as the orientation distribution functions (ODF) method. The textures at low degrees of deformation have been found to be similar to the rolling texture of pure Ni cold rolled to similar levels. With increasing degree of deformation, the texture in Ni3Al(B) changes to alloy type at reductions greater than 45%. This texture is characterized by the presence of a remarkably strong rotated Goss component over and above the Brass (Bs) component. Transmission electron microscopy of thin foils of the material cold rolled by 65% and more shows evidence of twinning. X-ray diffraction analysis indicates a structural change in the material from L12 to DO22 with the progress of cold work. An attempt has been made to explain the texture development in terms of this structural transformation.

Development of cold rolling texture in Ni 3Al (B)

High temperature intermetallic compounds like Ni[sub 3]Al are potential candidates for structural applications. Ni[sub 3]Al has an L[sup [sub 2]] structure and is ordered up to its melting point. The L1[sub 2] ordered structure of Ni[sub 3]Al may develop by ordering in a disordered F.C.C. structure. Numerous studies on the formation of rolling texture have been carried out on a number of F.C.C. metals and their alloys. Such metals and alloys are known to exhibit three types of rolling texture: (1) [alpha]-brass type in materials of low stacking fault energy, (2) copper type in materials of medium stacking fault energy and (3) aluminium type in materials of very high stacking fault energy. However, very little work has been done on the development of deformation texture in intermetallic compounds. The limited literature available in this area suggests that the textures developed in intermetallics are somewhat different from those of common F.C.C. metals and alloys. The formation of deformation textures in these materials are not yet fully understood. In this paper some new observations on the development of cold rolling texture in Ni[sub 3]Al(B) are reported.

Effect of Copper Alloying on the Development of Cold Rolling Textures in Extra Low Carbon Steels

Effect of Copper Alloying on the Development of Cold Rolling Textures in Extra Low Carbon Steels

Development of Cold-Rolling Textures in Pure Ti

Hot bands of pure Ti, obtained with thermomechanical processing, were cold-rolled up to 90% reduction in thickness, and the development of the cold-rolling texture was investigated in detail with the crystallite orientation distribution function analysis. Through the thermomechanical processing, which consisted of 97.5% hot rolling at 700deg C, followed by annealing for 1 h at the same temperature, a strong {l brace}1013{r brace} recrystallization texture wad developed in these hot bands. This texture was quite unstable during cold-rolling, so that it was considerably weakened after 30% cold-rolling. This texture change was caused mainly by extensive twinning which was followed by slip rotations. At rolling reductions between 30 and 50%, a basal texture having its center at the {l brace}0001{r brace} orientation was developed remarkably. To this texture change, slip rotations contributed much more than twinning. At rolling reductions above 50%, deformation by slip induced this {l brace}0001{r brace} orientation to rotate about its axis lying parallel to the rolling direction toward the {l brace}2115{r brace} orientation. This rotation was terminated at the {l brace}2115{r brace} orientation, and at rolling reductions above 80%, the {l brace}2115{r brace} orientation become the stable end orientation of the cold-rolling texture. (orig.).

α鉄の冷間圧延集合組織の発達過程

α鉄の冷間圧延集合組織の発達過程