Development of Computer-Assisted System for Microstructural Design and Control of Steel

开发了用于钢的微观结构设计和控制的计算机辅助系统，该系统涉及（i）物理性能数据库的构建和（ii）相变动力学的计算方法。得到的结果如下： 1．建立了铁基合金相图数据库。收集了1990年以后的相关论文，并结合了ASM International以前的汇编。通过使用面向对象的数据库系统MOOD.2，该信息可用于互联网上的全球数据库服务。建立了铁基合金扩散系数数据库。分析了扩散系数与熔点之间的关系。该方法对于没有实验信息的扩散数据的估计很有用。 3．建立了铁合金液相表面能和粘度数据库。还给出了估算表面能的计算方法。 4．评估了C与铁素体中合金元素之间的相互作用，它强烈影响碳钢的蠕变强度。 5．基于非线性扩散方程，通过计算机模拟预测相分解。 6．阐明了磁有序和化学有序对相平衡的影响。结果表明，磁有序和化学有序之间的相互作用显着影响相稳定性。7．定量分析了晶界移动时溶质的拖曳效应。8．建立了平均晶粒半径与双相α相和β相体积分数之间的关系。

Computer-assisted system for microstructural design and control of steels has been developed, which is concerned with (i) construction of database of physical properties and (ii) computation al approach of kinetics of phase transformation. The results obtained are as follows.1. The database on phase diagrams of iron base alloys has been constructed. The related papers after 1990 are collected which combines with the previous compilations by ASM International. This information is available for world -wide database service on the Internet by the use of an object-oriented database system MOOD.2. The database on diffusion coefficient of iron base alloys has been constructed. The relation between diffusion coefficients and melting point is analyzed. This method is useful for the estimation of diffusion data where there is no experimental information.3. The databease on the surface energy and viscosity of liquid phase in iron alloys has been constructed. The computational method of estimating surface energy is also presented.4. The interaction between C and alloying elements in ferrite is evaluated and it strongly affects the creep strength of carbon steels.5. Phase decomposition is predicted by computer simulation based on non-linear diffusion equation.6. Effect of magnetic and chemical ordering on phase equilibria is clarified. It is shown that the interaction between magnetic and chemical ordering significantly affects the phase stability.7. Solute drag effect is quantitatively analyzed when the grain boundary is moving.8. The relation between mean grain radii and volume fractions of alpha and beta phases of dual-phase is established.