Characterization of the intermetallic G-phase in an AISI 329 duplex stainless steel
Characterization of the intermetallic G-phase in an AISI 329 duplex stainless steel
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DOI：
10.1023/a:1018669217124
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发表时间：
1997-09-01
影响因子：
4.5
通讯作者：
Metauer, G
中科院分区：
文献类型：
--
作者：
Mateo, A;Llanes, L;Metauer, G
当在中间温度范围（250-500 ℃）内老化时，双相铁素体-铁素体不锈钢易受各种分解过程的影响。这些现象之一是金属间G相的沉淀。在本调查中，G相的晶体结构和化学成分，在铁素体相的AlSI 329双相不锈钢沉淀，研究了电子显微衍射和能量色散X射线光谱。确定了G相的空间群为F4/m（3）/bar 2/m，晶格常数为铁素体基体的4倍。G相的析出机制与富Cr区和富Fe区的铁素体分解有协同关系。在此基础上，研究了铁素体基体和G相的结构接近性。进一步的分析可以表明，亚稳分解导致的铁素体结构，这是结晶不稳定的，并作为一个附加的网站的发展G-相的原子位置rerearrangements劣于原子距离的interdomain。
Duplex austenite-ferrite stainless steels are susceptible to a variety of decomposition processes when aged within the intermediate range of temperatures (250-500 degrees C). One of these phenomena is the precipitation of the intermetallic G-phase. In the present investigation, the crystal structure and the chemical composition of the G-phase, precipitated in the ferritic phase of an AlSI329 duplex stainless steel, is studied by electron microdiffraction and energy dispersive X-ray spectroscopy. It is determined that the space group of the G-phase is F 4/m (3) over bar 2/m with a lattice parameter four times that of the ferritic matrix. The precipitation mechanism of the G-phase showed a synergetic relation with the ferrite decomposition in Cr-rich and Fe-rich domains. Based on the obtained results, the structural proximity of ferrite matrix and G-phase has been studied. Further analysis allows to suggest that the spinodal decomposition leads to an interdomain of a ferritic structure which is thermodynamically unstable and serves as a precursory site to the development of the G-phase by atomic position readjustments inferior to the atomic distances.