偏析干预下体心立方金属再结晶织构竞争

Recrystallization Texture Competition Mediated by Segregation Element in Body-Centered Cubic Metals

采用实验和模拟相结合的方法研究了含偏析元素Sb的体心立方Fe-3%Si合金再结晶织构间的竞争。结果表明,偏析元素通过抑制γ(<111>//ND,ND为轧面法向)再结晶晶粒向α(<110>//RD,RD为轧制方向)等低储能形变晶粒的入侵,削弱γ再结晶织构组分、强化α等再结晶织构组分,形变织构和临界入侵半径是影响偏析效应的主要因素。构建了基于形核与长大动力学的偏析干预下再结晶织构竞争关系模型,模拟了γ再结晶晶粒向α形变晶粒入侵行为对临界入侵半径和形变织构的依赖性及其动力学过程。指出偏析元素可以通过延长入侵孕育期并降低入侵速率来抑制γ再结晶晶粒消耗α形变晶粒,抑制效果随临界入侵半径和γ形变织构含量的提高先增强后减弱。

Recrystallization texture is determined by the competition among various texture components during nucleation and grain growth.The stored energy and orientation gradient depend on the grain orientation in the deformed microstructure.Texture components,nucleating at positions with high stored energy and a sharp orientation gradient have kinetic advantages,can consume the nucleation sites and potential growth space of recrystallized grains in adjacent deformed grains.Segregation elements can hinder nucleation and growth of recrystallization grains by reducing grain boundary mobility,and thus prevent texture components with kinetic advantages from invading adjacent deformed grains.It is valuable to provide a basis for precise recrystallization texture design and control by investigating the competitive relations among recrystallization texture components under the intervention of segregation elements.The recrystallization texture competition in a body-centered cubic Fe-3%Si alloy containing Sb was studied through experiment and simulation.It was found that the segregation element can weaken theγ(<111>//ND,ND—normal direction)and strengthen theα(<110>//RD,RD—rolling direction),as well as other recrystallization texture components with low stored energy,by inhibiting the invasion ofγ-recrystallized grains into adjacent deformed grains.The two dominant factors for segregation effects are deformation texture and critical invasion radius.A quantitative model,based on nucleation and growth kinetics,was proposed to explore the effect of critical invasion radius and deformation texture on recrystallization texture competition mediated by segregation elements.It was found that segregation elements can prolong the invasion incubation period and reduce the invasion rate to inhibit the consumption ofα-deformed grains byγ-recrystallized grains.The inhibition effect initially strengthened and then weakened with the increasingγdeformation texture.