MICROSTRUCTURE AND STRAIN-HARDENING OF STEELS

In the present work, the relation between metallurgical microstructures and strain hardening behaviour of both fee and bce steels was investigated. In order to obtain large strains, a new experimental method was developed and the data mathematically prepared for further analysis. It was found that the strain hardening rate increases with decreasing particle size or increasing yield stress of ferritic steels. The strain hardening rate is found to be correlated to the specific microstructure. A new model was formulated to describe large deformations. This has been done on the basis of already existing models. According to the new model, the strain hardening in stage IV is caused by the dislocations in cell interiors instead of those in the cell walls.