摘要铁铬合金是双相不锈钢中重要的基础合金,常常被应用在高温、辐射、应力等工作环境下，因此，其组织的稳定性非常重要。在辐照和高温条件下，Fe-Cr合金会产生富Cr的α′沉淀相，导致不锈钢塑、韧性和耐蚀性降低。因此，研究Fe-Cr合金的相分解及α′相的粗化行为对成分选择和组织性能预测有重要参考价值。本文利用Cahn-Hilliard相场方程，建立了Fe-Cr合金失稳分解的相场动力学模型。通过对该合金在不同温度和不同浓度下α´相的微观组织、体积分数、半径和颗粒数密度随时效时间的变化规律，研究了Fe-Cr合金分解过程中的动力学变化过程，为合金服役和设计提供参考。主要的研究结果如下：25300
    随着Cr浓度的上升，相分解的速度变快，但当Cr浓度温度很低，时效温度足够高时，Fe-Cr合金中第二相分解机制为形核长大，此时第二相长大速度明显增加。Cr浓度相等时，随着温度的升高，失稳分解速度变快，高温下α′相平衡体积分数变小，α′相颗粒半径变大。
关键词：Fe-Cr合金，相分解，微观组织
毕业论文设计说明书外文摘要
Title: Nano phase separation dynamics in the ferritic phase field quantitative
Abstract
Fe-Cr duplex stainless steel alloy is an important base alloy, it is often applied at high temperatures, radiation, stress and other work environment, therefore, very important to the stability of their organization. Under irradiation and high temperature conditions, Fe-Cr alloys will produce Cr-rich α 'precipitate phase, resulting in a stainless steel plastic, toughness and corrosion resistance decrease. Therefore, the coarsening behavior of Fe-Cr alloy phase decomposition and α 'phase of component selection and organization performance prediction has important reference value. In this paper, phase field Cahn-Hilliard equation, phase field dynamics model Fe-Cr alloy instability decomposition. By microstructure of the alloy at different temperatures and different concentrations of α'-phase volume fraction, radius, and particle number density variation effect at any time, to study the dynamics of change in Fe-Cr alloy in the decomposition process, an alloy service and designed to provide a reference. The main findings are as follows:
With the increase in Cr concentration phase decomposition of speed increases, but when the temperature is very low Cr concentrations, the aging temperature is high enough, Fe-Cr alloy in the second phase decomposition mechanism of nucleation and growth, while the second phase length Great speed increased significantly. When the Cr concentration equal to, as the temperature rises, instability decomposition rate becomes faster, the high temperature α 'equilibrium volume fraction is small, α' phase particles larger radius.
Keywords： Fe-Cr alloy, Phase decomposition, Microstructure
目   录
1    引言    1
1.1 研究背景    1
1.1.1  Fe-Cr合金的基本性能    2
1.1.2  Fe-Cr合金相分解的研究现状    2
1.1.3  存在的问题    3
1.2 相变动力学理论    3
1.2.1  经典理论    4
1.2.2  非经典形核    5
1.2.3  匀相转变    6
1.3 计算机模拟在材料中的应用    7
1.4 相场方法    8
1.4.1  相场法的原理    9
1.4.2  相场法的特点    10
1.4.3  相场法的应用    10
1.5 本论文研究内容    11
2  研究方法    11
2.1  相场方法    11 纳米相在铁素体中分离动力学的定量相场研究:http://www.751com.cn/cailiao/lunwen_19171.html