具层状细观结构的PD3珠光体钢的细／宏观力学分析

对层状细观结构的ＰＤ３珠光体钢进行了细／宏观分析。基于层片界面间应力、应变相容条件和复合材料混合律，得到了层状均匀夹杂的本构方程。联合这些方程与Ｋ－Ｂ－Ｗ自相容模型建立了细观与宏观间的转换。由此得到在单调和循环载荷下材料的整体响应和细观结构局部应力的演化。分析发现在薄渗碳体层中局部应力很高。这是由于软铁素体层在循环载荷下其塑性流动不断增强使载荷转向硬相。由笔者推得的强度与微结构层厚度尺寸平方根成反

The Micro/Macro Mechanic Analysis of PD3 Pearlitic Steel with Layered Microstructures

A micro/macroscopic analysis of PD3 pearlitic steel with layered microstructure is carried on.Based on the compatibilit conditions of stress and strain at the interface between two layers as well as the mixed law of composites,constitutive equations of an effective homogeneous inclusion are obtained.combining these equations with the K B W self consistent model,the micro macroscopic transition has been estabilished.It turns out that the analysis is capable of determining the overall responses of materials as well as local stress evolution in microstructure under monotonic and cyclic loading.It is found that stress in the thin cementite layer is very high.This is caused by intersification of the local plastic flow of the soft ferrite layer in which more loading is transferred cycle by cycle to the hard phase.Furthermore,a strength dimension law that the strength is inversely proportional to the square root of the layer thickness is developed to explain the high strength of the cementite layer.