下贝氏体碳化物形态及来源  

Morphology and Source of Lower Bainitic Carbide

作　　者：王家军[1] 方鸿生[1] 杨志刚[1] 

机构地区：[1]清华大学

出　　处：《钢铁研究学报》1997年第5期33-37,共5页Journal of Iron and Steel Research

基　　金：国家自然科学基金及国家教委开放实验室基金

摘　　要：用ＴＥＭ观察了Ｆｅ－１．０８Ｃ－３．９５Ｃｒ合金下贝氏体碳化物（θ）的形态，发现θ呈棒状或楔状。实测碳化物的主轴方向近似与［１００］＊θ或［０１０］＊θ平行，楔根源于贝氏体铁素体—奥氏体界面，或部分深入铁素体内部而形成在相界面钉扎的特殊形态。提出铁素体（α）可能按激发形核—扩散控制台阶（ＳＮＬＧ）机制长大，θ与α竞争长大，α的形成过程决定了θ的形态及分布。The morphology of lower bainitic carbide ( θ ) formed in an Fe 1.08C 3.95Cr alloy has been studied by TEM. The experimental results show that θ phase is bar like or wedge shaped, with its long axes approximately parallel to * θ or * θ , and the root of a wedge shaped carbide originating at the bainitic ferrite ( α )/austenite interface, or partially penetrating into ferrite. The occurrence of carbide at the interface between the product and the matrix gives rise to the moving interface being locked. It has been proposed that the α component of bainite may be formed through sympathetic nucleation ledgewise growth mechanism while θ grows competitively with the α phase which usually embedding θ particles, as a result, promoting the overall kinetics of bainitic reaction. The morphology and distribution of the θ phase is determined to some degree by the precipitating process of the α component.

关 键 词：贝氏体 竞争长大机制 碳化物 SNLG机制 

分 类 号：TG113.12[金属学及工艺—物理冶金]