Vliv extrémní plastické deformace metodou ECAP na strukturu a vlastnosti ocelí

Abstract

It was studied development of microstructure and mechanical properties for low carbon steel and stainless steel after equal channel angular pressing (ECAP) by road Bc with the working temperature 300°C. Analyzes of structure were made by optical microscope and development of substructure was analyzed by reflection electron microscope (REM) and transmission electron microscope (TEM). Development of mechanical properties of the samples was determined by tensile test. Development of microstructure and mechanical properties were also studied for low carbon steel after ECAP and recrystallization annealing. Each pass of ECAP led to grain refining. This tendency increased with the expanded number of passes and after 6 passes of ECAP was average grain size 1μm ±0,5μm. Changes in the microstructure after ECAP increased significantly mechanical properties, but adversely affected the ductility. Therefore it was applied recrystallization annealing, which changed deformed microstructure to equiaxed grains with variable size. Applied recrystalization annealing caused that the mechanical properties after ECAP were lower than for ECAP, but higher than for initial state.