Microstructural evolution of two-way cold rolled 12Cr ODS steel under 1073 - 1373 K annealing
Microstructural evolution of two-way cold rolled 12Cr ODS steel under 1073 - 1373 K annealing
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双向冷轧12Cr ODS钢在1073 - 1373 K退火下的显微组织演变
DOI：
10.1016/j.nme.2020.100792
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发表时间：
2020
影响因子：
2.6
通讯作者：
Abe Hiroaki
中科院分区：
文献类型：
--
作者：
Shen Jingjie;Nagasaka Takuya;Muroga Takeo;Yang Huilong;Kano Sho;Abe Hiroaki
采用电子背散射衍射技术、透射电镜和维氏硬度测量等方法，系统研究了冷轧12 Cr ODS钢在1073-1373 K退火后，厚度减薄60%~ 90%时的组织演变和硬度变化。当试样厚度减薄60%时，加热至1273 K发生回复，硬度逐渐下降，随后在1373 K发生再结晶，硬度明显下降。相比之下，对于与75%和90%的厚度减少的试样，观察到在1273 K，这是100 K低于60%的厚度减少，和400 K低于未经进一步冷轧，表明更高的厚度减少刺激在较低的温度下发生再结晶。此外，厚度压下90%的试样在1073 K和1173 K下发生部分再结晶，沿着终轧方向产生等轴晶带，没有氧化物颗粒或氧化物颗粒密度较低，在1273 K及以上发生完全再结晶，形成氧化物颗粒密度高、等轴晶比例较小的粗大细长晶。这些双峰晶粒可能归因于氧化物颗粒在基体中的不均匀分布，这些颗粒在冷轧过程中部分溶解，并在热退火后重新析出。
Microstructural evolution and hardness variations of cold rolled 12Cr ODS steel with 60%–90% thickness reductions after 1073–1373 K annealing were systematically studied by electron backscatter diffraction technique, transmission electron microscopy, and Vickers hardness measurements. Recovery took place with heating up to 1273 K in specimens with 60% thickness reduction accompanying with gradual hardness decrease, and followed by recrystallization at 1373 K with an evident hardness reduction. By contrast, regarding specimens with 75% and 90% thickness reductions, recrystallization was observed at 1273 K which is 100 K lower than that of 60% thickness reduction, and 400 K lower than that of as-fabricated specimen without further cold rolling, indicating that a higher thickness reduction stimulated the onset of recrystallization at a lower temperature. Furthermore, partial recrystallization was characterized at 1073 K and 1173 K in the specimen with 90% thickness reduction, which produced equiaxed grain bands along the final rolling direction with none/lower density of oxide particles, and full recrystallization occurred at 1273 K and above, forming coarse elongated grains with high density of oxide particles and a smaller fraction of equiaxed grains. These bimodal grains were probably ascribed to heterogeneous distribution of oxide particles in the matrix, which were partially dissolved during cold rolling process, and re-precipitated after the thermal annealing.