EFFECT OF SEVERE PLASTIC DEFORMATION ON STRUCTURE AND PROPERTIES OF AUSTENITIC AISI 316 GRADE STEEL
The article presents results of investigation of structure and properties of austenitic steel grade AISI 316 after application of Equal Channel Angular Pressing (ECAP) at the temperature of approx. 290C. The ECAP method leads to significant improvement of strength of investigated material. Investigation of structure was made by combination of TEM and FEG SEM together with EBSD. Statistic evaluation of angular disorientation and of size of grains/sub-grains was also made with use of electron diffraction (EBSD) in combination with scanning electron microscope FEG SEM Philips. It was proven that the ECAP method enables obtaining of ultra fine-grained austenitic structure. It was established with use of the EBSD technique that after 8 passes through the ECAP die the sub-grains with misorientation angles smaller than 10 formed less than 20% of the final structure. Average size of austenitic grains with high-angle boundaries after 8 passes was approx. 0.1m.
Equal Channel Angular Pressing, its Effect on Structure and Properties of the Constructional Steel St3
The steel St3 was processed by equal channel angular pressing. The structure and properties of the steel after two ECAP passes were determined. The different routes (Bc and C) resulted in different microstructure evolution during the equal channel angular pressing. It has been shown that equal channel angular pressing is a very suitable method for produce materials with good mechanical properties.
Structure and strength after large strain deformation
Abstract A detailed structural characterisation is the basis for an analysis of the structure–flow stress relationship in deformed metals. This is demonstrated for aluminium (99% purity) deformed to very large strain by cold rolling. The analysis is repeated for aluminium of similar purity deformed to large strains by accumulative roll bonding (ARB), which introduces a significantly different microstructure than that observed after cold rolling. The structure–flow stress relationship of ARB materials is discussed and related to that observed for cold rolled samples.