A method of producing very fine ferrite grains by means of hot forming

摘要

It is well known that refining the grain size of metals should lead to an improvement in the mechanical properties both of strength and of toughness. Therefore, a method has to be improved for the formation of very fine ferrite grains during hot rolling. By means of hot compression tests using an IF-type steel and a HSLA steel the effect of chemical composition, deformation temperature, strain and strain rate on the resulting ferrite grain size has been investigated. By optimizing the different process parameters during hot deformation, a ferrite grain of ASTM 15 can be produced. By means of the Hall-Petch relationship an estimation of the influence of the influence of ferrite grain refinement on the mechanical properties can be given.