Characteristics of the Cold-Rolling Texture in a Multi-Layered Material Composed of SUS301 and SUS420J2 Steels

Abstract

A multi-layered composite material composed of alternating SUS301 and SUS420J2 steels, prepared by hot-rolling bonding, shows a superior strength and ductility balance than the components. Few researches have been addressed on texture features of structural multi-layered materials during cold-rolling. In the present work, cold-rolling with three reductions (20%, 40% and 65%) in thickness was conducted on both the two monolithic steels (SUS301 and SUS420J2) and the multi-layered material consisting of SUS301 and SUS420J2 components. Texture and microstructure development during the cold-rolling deformation in both the monolithic steels and multi-layered material were investigated by using EBSD technique. It was found that austenite phase in SUS301 component of the multi-layered material showed weaker h110i==ND texture as compared to the monolithic SUS301 steel although the similar texture characteristics appeared in both conditions. On the other hand, the martensite phase in SUS420J2 component of the multi-layered material showed stronger f112gh110i texture components than the h111i==ND and h100i==ND texture components that were dominant in the monolithic SUS420J2 steel. It is considered that the constraint condition and shear stress at component layer interfaces are significant for the formation of Brass component observed as the final stable orientation of austenite phase of the SUS301 steel in the multi-layered samples, and the formation of the f112gh110i texture of martensite phase of the SUS420J2 steel in the multi-layered samples during the cold-rolling deformation.

Interface Strengthening and Toughening Mechanism of Hot Rolled Multilayer TWIP/40Si2CrMo Steels

“…In addition, with the increase of hot rolling reduction, the hardness of the TWIP steel layer and 40Si2CrMo steel layer both increased. This was because the number of dislocations in the constituent layers increases, and the packing and winding of dislocations further hinder the movement of dislocations, resulting in work hardening, which increases the hardness of the constituent layer [21,22]. Figure 7 shows the microhardness values of multilayer TWIP/40Si2CrMo steels with different hot rolling reductions.…”

Establishment and Optimization of Angle Dispersive Neutron Diffraction Bulk Texture Measurement Environments

“…It was reported that the 65% cold rolling of similar multilayered steel composite sheet composed of 13 austenite layers and 12 martensite layers in the sandwich type resulted in the strongest {112}h110i component of martensite texture as well as strong {111}huvwi-fiber and {001}h110i texture components. 24) Because most of martensite blocks are not elongated toward the rolling direction anymore as shown in Fig. 6 and the rotated cube {001}h110i component still exists after the rapid annealing at 1273 K for 120 s in the austenite single phase region of SUS420J2, the partial recrystallization is speculated to take place through the formation of {111}h112i at the expense of {112}h110i component.…”

“…The strong {110}h211i component, the strong {110}h001i component and the relative weak {112}h111i-{113}h332i component exhibit the similar annealing characteristics of cold rolled metastable austenite of SUS304 during rapid annealing. 26) Because the 50% cold rolling cannot enable the austenite in SUS301 steel layers to completely transform into martensite, 24) the fine grained equiaxial austenite as shown in Fig. 6 is thought to partially form through the static recrystallization and partially form through the martensite-to-austenite reverse transformation.…”

Friction stir welding of multilayered steel

“…1 Multilayered steel with enhanced deformation behaviour and tensile properties consisting of alternating layers of ductile austenitic steel and brittle martensitic steel has been subject to various investigations. [2][3][4][5][6] Inoue et al 2 showed a transition of the fracture behaviour of the martensitic layer from brittle cleavage to ductile shear just by reducing the layer thickness in a hot rolled laminate. More than 50% elongation of as quenched martensite was achieved under tensile loading using a laminated composite consisting of conventional martensitic and austenitic steel.…”

“…3 Nambu et al 4 demonstrated tremendous improvement in tensile ductility by increasing the bonding strength in a brittle/ductile multilayered structure. Detailed investigations concerning strain field computation 5 and microtexture development for different cold rolling reductions 6 were carried out for multilayered steel composed of martensitic and austenitic layers. However, no successful welding of that material has been reported so far.…”