双相不锈钢内界面分布特征及演变机理研究

项目名称： 双相不锈钢内界面分布特征及演变机理研究

项目编号： No.51471100

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 一般工业技术

项目作者： 方晓英

作者单位： 山东理工大学

项目金额： 84万元

中文摘要： 内界面（晶界和相界）分布特征对多晶材料(尤其是细晶材料)的性能和行为具有重要影响。本项目拟以双相不锈钢为研究对象，主要采用基于EBSD分析的界面五参数法并结合TEM，AFM，XRD等技术系统研究经多种大变形退火处理后合金组织中内界面分布（IPD）特征及其演变机理。首先，通过不同大形变退火工艺在合金中得到相对细晶组织，统计不同晶粒水平下的晶界面分布（GBPD）和相界面分布（PBPD）,并进一步分析特定晶界取向差下的GBPD和两相取向关系(OR)下的PBPD,获得可改善某种或多种合金性能的IPD特征及其诱导工艺组合；其次，针对产生不同IPD的典型工艺，追踪合金的组织演变情况，探讨双相合金退火过程中再结晶和相变耦合作用与IPD演变之间的关联性。最后运用金属晶体学、塑性变形、回复再结晶、相变和晶粒长大等理论来阐释双相不锈钢IPD的演变机理。

中文关键词： 晶界工程；相界面；界面结构

英文摘要： It is well recognized that many properties of polycrystalline materials, especially those with fine-grained microstructure, are determined to a large extent by their internal interfaces. The features of interfacial plane distribution (IPD) will be investigated extensively by means of five-parameter analysis(FPA) based on electron back-scatter diffraction(EBSD) measurements and other techniques such as TEM, atom force microscopy(AFM), XRD in duplex stainless steels(DSSs), which are initially processed by various strain and annealing treatments. First, relatively fine-grained microstructure will be produced by different large strain and subsequent annealing and the resulted grain boundary plane distribution (GBPD) and phase boundary plane distribution (PBPD) are to be analyzed at different levels of grain size. In the meanwhile, the GBPDs with various misorientation and PBPDs with various orientation relationships (ORs) will be further studied as well. Second, microstructural development will be traced during several typical thermomechanical processing which have introduced different IPDs. And also, correlations between IPD features and the related microstructure including pre-strained sub-microstructure, grain size, grain boundary character distribution (GBCD), ORs, length/number fractions of grain boundary and phase boundary, volume fractions of ferrite and austenite and etc., are to be studied systematically. Third, based on the experimental results, the IPD evolution mechanism will be clarified by the metallography theories associated with crystallography, plastic deformation, recovery and recrystallization, phase transformation and grain growth. Finally, after mechanical properties and corrosion resistance testing in DSSs as processed, the desired thermomechanical processing will be found to improve certain mechanical properties or corrosion resistance as the favorable IPDs are achieved, which will be meaningful for the optimization of IPDs in duplex alloys.

英文关键词： grain boundary engineering;interface;interface structure