Low-angle boundary engineering for improving high-cycle fatigue property of 430 ferritic stainless steel
Low-angle boundary engineering for improving high-cycle fatigue property of 430 ferritic stainless steel
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DOI：
10.1007/s10853-020-04555-0
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发表时间：
2020-03
影响因子：
4.5
通讯作者：
S. Kobayashi;Weitao Yang;Yuuki Tomobe;R. Okada;S. Tsurekawa
中科院分区：
文献类型：
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作者：
S. Kobayashi;Weitao Yang;Yuuki Tomobe;R. Okada;S. Tsurekawa
为改善430铁素体不锈钢的疲劳性能，研究了基于小角度晶界网络控制的晶界工程技术。通过电子背散射衍射测量，定量地评价了在高压下率下冷轧的试样在退火过程中亚晶界结构的发展。通过冷轧至95%，随后在973 K下退火600 s，产生具有高LAGB分数（FL= 54%）的细亚晶组织，形成尖锐的{100}和{111}织构。在GBEed样品中，LAGB相互连接形成网络。核平均取向差图表明，LAGB网络中的位错密度高于再结晶晶粒中的位错密度，特别是在LAGB附近。比较了具有不同程度LAGB网络的试样与退火的商用430不锈钢的高周疲劳性能。疲劳后GBE试样的核平均取向差图显示，在循环变形过程中位错密度下降，而细晶结构和高比例的LAGB保持。结果表明，晶粒细化和引入高含量的LAGB可以获得更高的疲劳强度和更长的疲劳寿命的430不锈钢。
Grain boundary engineering (GBE) based on the control of a low-angle grain boundary (LAGB) network was investigated to improve the fatigue property in 430 ferritic stainless steel. The development of a subboundary structure during annealing in a specimen that was cold rolled at a high reduction ratio was evaluated quantitatively by electron backscatter diffraction measurements. The fine subgrain structure with a high fraction of LAGBs (FL= 54%) was produced with the formation of a sharp {100} and {111} texture by cold rolling to 95% with subsequent annealing at 973 K for 600 s. The LAGBs interconnected to form networks in the GBEed specimen. The kernel average misorientation maps suggest that the dislocation density within the LAGB network was higher than that in the recrystallized grains, particularly near the LAGBs. The high-cycle fatigue property in specimens with different magnitudes of LAGB networks was compared with that in the annealed commercial 430 stainless steel. The kernel average misorientation maps for the post-fatigued GBEed specimen reveal that the dislocation density decreased during cyclic deformation, whereas the fine-grained structure and high fraction of LAGBs were maintained. It was concluded that the grain refinement and introduction of a high fraction of LAGBs can achieve a higher fatigue strength and longer fatigue life for 430 stainless steel.