A quantitative metallurgical understanding of the relationship between steel microstructure and properties is essential for optimising both product and upstream and downstream steel manufacturing processes. In this work, improved structure�property relationships for strength and hardness have been derived for multiphase microstructures, including bainite and martensite. Laboratory hot rolling and heat treatments have been performed to generate specific microstructures, for mechanical testing and detailed metallographic analysis of the key parameters contributing to the properties, such as grain and lath size. Nanohardness was found to be very useful for determining the properties of individual components in a mixed structure. EBSD analysis was successfully applied to characterise bainitic grain sizes in a novel way. Equations for the strength and tensile stress�strain behaviour of both single phase and multiphase microstructures have been developed. Approaches for modelling mixed structures other than a simple law of mixtures have been considered, including a self-consistent model, and finite element methods in which the tensile deformation of both actual and artificial microstructures were simulated. Computer modules have been developed for calculating the properties; suitable for standalone use or linking with hot rolling phase transformation models. The steels considered were mainly CMn, low alloy and dual phase grades but the metallurgical principles of the models are applicable to a wide range of products.
Bibliographic Reference: EUR 20880 EN (2003), 284pp. Euro: 35
Availability: EUR-OP reference: KI-NA-20880-EN-S Available from EUR-OP sales agents URL: http://www.publications.eu/general/en/publications_en.htm
ISBN: ISBN: 92-894-6255-8
Record Number: 200317103 / Last updated on: 2003-11-05
Original language: en
Available languages: en