Computational modeling of the influence of the interlamellar spacing in pearlitic steel

Other conference contribution, 2010

On the microscopic scale pearlite is a two-phase material with hard and brittle cementite lamellas that are embedded in a softer ferrite matrix. In each pearlite colony the cementite has a preferred direction whereas the crystallographic directions for the ferrite are the same within a nodule. An important microstructural property of a pearlitic steel is the distance between the cementite lamellas, i.e. the interlamellar spacing. It is well-known from experiments that a decreased interlamellar spacing results in an increased strength of the material. In this contribution, different modeling assumptions will be discussed how to predict such a dependence of the interlamellar spacing (or in other words the size dependence of the ferritic matrix between the cementite lamellas). The key modeling assumption that is adopted for the ferrite is a crystal plasticity model with gradient hardening.