Microstructures and mechanical properties in ultra fine-grained oxide-dispersion ferritic stainless steels
Microstructures and mechanical properties in ultra fine-grained oxide-dispersion ferritic stainless steels
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超细晶粒氧化物弥散铁素体不锈钢的显微组织和机械性能
DOI：
10.2355/isijinternational.40.suppl_s174
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发表时间：
2000
期刊：
影响因子：
--
通讯作者：
S. Takaki
中科院分区：
文献类型：
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作者：
Y. Kimura;Shinichi Suejima;H. Goto;S. Takaki
研究了由机械球磨粉末制备的含24%(质量分数)铬铁素体的超细晶粒氧化物弥散型钢的组织和性能。在Ar气氛中机械球磨Fe、Cr和Y_2O_3粉末混合物，然后在约1100K下固化。经720K机械球磨后，粉末颗粒内形成了纳米铁素体颗粒结构。对于Y_2O_3颗粒。观察到它们不仅被粉碎到几个纳米级，而且在MM过程中也会分解，然后在1200K左右的热处理中，Y2O_3和YCrO_3等氧化物以超细晶相的形式析出。这种超细氧化物颗粒有效地抑制了基质颗粒的长大。添加1vol.%Y_2O_3的样品，由于直径约10 nm的氧化物颗粒的齐纳钉扎效应，在1573K-3.6K的热处理后仍能保持0.4μm的超细铁素体颗粒。在小于1μm的晶粒度范围内，随着铁素体晶粒度的减小，块体的抗拉强度显著提高，当Y2 O_3加入量为1%时，抗拉强度达到1.93 Gpa，最小平均晶粒度为0.16μm。
Microstructures and mechanical properties were investigated in ultra fine-grained oxide-dispersion steels with 24 mass% Cr ferrite matrix fabricated from mechanical milled powders. Powder mixtures of Fe, Cr and Y2O3 were mechanically milled in an argon gas atmosphere and then consolidated at around 1100K. After 720 ks mechanical milling (MM), nanocrystalline ferrite grain structures were formed within powder particles. As for Y2O3 particles. It was observed that they were not only crushed to several nanometers but also decomposed during MM, and then oxides like Y2O3 and YCrO3 finely precipitated in ultra fine grained structure on annealing at around 1200K. Such ultra fine oxide particles effectively retarded the growth of matrix grains. The sample with 1 vol.% Y2O3 addition maintained ultra fine ferrite grains of 0.4 μm even after the annealing of 1573 K-3.6 ks by the Zener pinning effect of the oxide particles of about 10 nm in diameter. Tensile strength of the bulk samples markedly rose as the ferrite grain size became smaller in the grain size range below 1 μm and reached 1.93 GPa for the bulk sample with 1 vol.% Y2O3 addition and with the smallest mean grain size of 0.16 μm.