α相区预变形对工业纯铁α-γ-α相变循环{011}/{011}近奇异晶界的影响  

Influence of pre-deformation inαphase region on{011}/{011}near-singular grain boundaries duringα-γ-αphase transformation of commercial pure iron

作　　者：匡竟成 王卫国 林琛 Gregory S Rohrer 陈松 林燕 KUANG Jing-cheng;WANG Wei-guo;LIN Chen;Gregory S Rohrer;CHEN Song;LIN Yan(Institute of Grain Boundary Engineering,Fujian University of Technology,Fuzhou 350118,China;School of Materials Science and Technology,Fujian University of Technology,Fuzhou 350118,China;Department of Materials Science and Engineering,Carnegie Mellon University,Pittsburgh,PA15213-38900,USA)

机构地区：[1]福建理工大学晶界工程研究所,福建福州350118 [2]福建理工大学材料科学与工程学院,福建福州350118 [3]Department of Materials Science and Engineering,Carnegie Mellon University,Pittsburgh,PA15213-38900,USA

出　　处：《材料热处理学报》2025年第1期59-71,共13页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金(52271027)。

摘　　要：具有密排面与密排面匹配特征的{011}/{011}近奇异晶界比一般晶界更耐蚀,研究此类晶界的形成条件、影响因素和形成机理,设法调控并提高其比例是增强体心立方金属晶界腐蚀抗力的根本途径。选用纯度为99.5%(质量分数)工业纯铁为研究对象,重点考察α相区预变形及α-γ-α相变循环对{011}/{011}近奇异晶界的影响。两个平行试样分别在300和910℃进行轧制变形量为40%的α相区预变形后,再进行α-γ-α相变循环。采用基于电子背散射衍射和五参数分析的晶界界面匹配表征方法测定上述各试样的{011}/{011}近奇异晶界比例。结果表明,经300和910℃预变形后再经α-γ-α相变循环的样品,其{011}/{011}近奇异晶界比例分别为7.95%和15.77%。重叠极图晶界迹线分析及相变晶体学分析指出,α相区预变形,可通过(1/2){011}<111->主滑移在纯铁中引入大量滑移带,相邻滑移带之间的界面具有{011}/{011}匹配特征。α相区预变形的样品加热至γ相区以及经冷却再次回到α相区的过程中,即完成α-γ-α相变循环的过程,依据Kurdjumov-Sachs相变机制,α相滑移带之间的{011}/{011}界面在进入γ相区时,有利于转变成γ相的{111}/{111}晶界,此类晶界经相变再次回到α相区时,也有利于转变成{011}/{011}近奇异晶界。经300℃预变形的样品在进入γ相区前,由于发生了大范围的再结晶,滑移带及其{011}/{011}界面留存较少,再经α-γ-α相变循环后,其{011}/{011}近奇异晶界比例较低;相反,经910℃预变形的样品在进入γ相区前,仍保留着很高密度的滑移带及其{011}/{011}界面,再经α-γ-α相变循环后,其{011}/{011}近奇异晶界比例较高。The{011}/{011}near-singular boundaries,which means the grain boundary is inter-connected by two{011}planes,are more resistant to corrosion attacks compared to the random boundaries.Studying the formation conditions,influencing factors,and mechanisms of such grain boundaries,and finding ways to regulate and increase their proportion,is the fundamental way to enhance the corrosion resistance of body centered cubic metal grain boundaries.Selecting industrial pure iron with the purity of 99.5%(mass fraction)as the research object,the effects of pre-deformation inαphase region andα-γ-αphase transformation on the formation of{011}/{011}near-singular boundaries were studied.Two parallel specimens were predeformed in theαphase zone with a rolling deformation of 40%at 300℃and 910℃,respectively,followed byα-γ-αphase transformation.The grain boundary inter-connection(GBIC)characterization method based on electron backscatter diffraction and five parameter analysis was used to determine the content of{011}/{011}near-singular grain boundaries for the above samples.The results show that the fraction of{011}/{011}near-singular grain boundaries in the samples predeformed at 300℃and 910℃and then subjected toα-γ-αphase transformation cycling is 7.95%and 15.77%,respectively.The analysis of overlapping pole diagram grain boundary traces and phase transition crystallography indicates that the predeformation in theαphase region can introduce a large number of slip bands into pure iron through(1/2){011}<111->main slip,and the interface between adjacent slip bands has{011}/{011}matching characteristics.During the process of heating the predeformed sample in theαphase region to theγphase region and cooling it back to theαphase region,i.e.completing theα-γ-αphase transformation cycle,according to the Kurdjumov-Sachs phase transformation mechanism,the{011}/{011}interface between theαphase slip bands is conducive to transforming into theγphase{011}/{011}grain boundary when entering theγphase region.When this typ

关 键 词：工业纯铁 近奇异晶界 预变形 相变循环 

分 类 号：TG178[金属学及工艺—金属表面处理]