Relevance of austenite conditioning on final microstructure homogeneity
Fine grained ferrite microstructures provide a good combination of strength and toughness in as-rolled products.However,together with refinement,microstructural homogeneity is also very important,mainly for toughness properties.Ferrite grain refinement results from microstructural changes in the austenite phase before it transforms.In conventional controlled rolling,a pancake austenite microstructure with accumulated strain is obtained prior to transformation.This requires the application of deformation at temperatures below the recrystallisation stop temperature (RST),this value being dependent on the chemical composition and processing parameters.In Nb microalloyed steels this temperature is the result of the interaction between deformation,softening mechanisms and Nb microailoying.The resulting ferrite grain size then depends on the final austenite grain size,the amount of retained strain and the cooling rate after deformation.
microstructural homogeneity microalloying austenite conditioning
B Lopez J M Rodriguez-Ibabe
CEIT and Tecnun Univ.Navarra,P.M.Lardizabal 15,20018 San Sebastian,Basque Country,Spain
国际会议
上海
英文
890-894
2008-09-26（万方平台首次上网日期，不代表论文的发表时间）