Effect of cross cold rolling and annealing on microstructure and texture in pure nickel

Lixia Wang,Haitao Ni,Lijun Zhao,Ping Ren,Xingpin Chen,Qing Liu,Tianhong Luo,Lin Mei,Yongfeng Ding

doi:10.1515/rams-2020-0016

Lixia Wang, Haitao Ni + Show 7 more

Open Access

https://doi.org/10.1515/rams-2020-0016

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Abstract

Abstract The microstructure and texture in pure nickel were investigated during multi-step cross cold rolling (CCR) and subsequent annealing. It was found that the deformation texture in the CCR nickel was dominated by Brass and rotated Brass about normal direction (ND) (Bs ND ) texture components, along with marginal cube textures. The resulted deformation textures had a significant effect on the recrystallization behavior. Annealing of the CCR nickel at 550°C for 1 h led to the formation of dominant <012> // ND fiber accompanied by minor rotated cube textures, rather than strong cube texture. Increasing the annealing temperature up to 800°C resulted in further enhancement of <012> // ND fiber textures. The possible reasons for recrystallization behavior in annealed CCR sample were discussed based on in-situ annealing experiments from two aspects of oriented nucleation and oriented growth theories.

Highlights

The microstructure and texture in pure nickel were investigated during multi-step cross cold rolling (CCR) and subsequent annealing
It was found that the deformation texture in the CCR nickel was dominated by Brass and rotated Brass about normal direction (ND) (BsND) texture components, along with marginal cube textures
The electron backscatter diffraction (EBSD) orientation image map (OIM) on the TD plane for deformed sample is displayed in Figure 3a, which depicts the microstructure character and identifies orientations of grains with different colors

Summary

Introduction

Abstract: The microstructure and texture in pure nickel were investigated during multi-step cross cold rolling (CCR) and subsequent annealing. The formation of the recrystallization cube texture in metal materials with medium to high SFE can be affected by processing parameters, such as change of strain path, strain reduction and annealing temperatures [7] Among these factors, the change of strain path during rolling (i.e. rotating the sample by 90∘ around the normal direction (ND) after each rolling pass, named by “cross cold rolling”) can dramatically alter the deformation texture. The investigation by Bhattacharjee et al [10] demonstrated the disappearance of preferential nucleation of cube grains during recrystallization in the cross-rolled pure nickel, and attributed the annealing twining to the resulted recrystallization texture. The reasons for the disappearance of strong cube texture; on the other hand, the evolution of recrystallization textures was tracked and discussed by ex-situ and in-situ annealing experiments during annealing of cross-rolled pure nickel

Experimental

Deformation microstructure and texture in CCR nickel

Recrystallized microstructure and texture in the annealed CCR nickel

Microstructure evolution during in-situ annealing in the CCR nickel

Texture evolution during in-situ annealing in the CCR nickel

Conclusion