Strain Induced OverEquilibrium Ferrite Fraction in Low Carbon Steel
CHEN Ying1,CHEN Qian1,HAO Ruihua2,ZHAO Xiaoli1
1. Institute for Structure Materials, Central Iron and Steel Research Institute， Beijing 100081, China； 2. Long Products Division， Baoshan Iron & Steel Bao Steel Branch Co Ltd, Shanghai 201900, China
Abstract：The microstructure evolutions during isothermal holding combined with subsequently accelerated cooling were investigated in deformed low carbon steel.It is found that overequilibrium ferrite volume fraction would exist at room temperature after heavy deformation at different temperatures nearby Ae3.Reverse transformation from ferrite to austenite would occur during isothermal holding.This relaxation phenomenon has a dynamic characteristic which is similar to C curve.Further,ferrite grain size would grow combined with the ferrite volume fraction decrease during isothermal hoding.But the stability of overequilibrium ferrite,no matter on volume fraction or on grain size,would increase with the deformation temperature drop.
2006, Vol. 41 
