Effect of plastic deformation on the formation of acicular ferrite

The effect of plastic deformation on the transformation of austenite to acicular ferrite in a Fe-Mn-Si-C alloy steel containing non-metallic inclusions was investigated. The transformation to acicular ferrite is retarded and the final fraction of acicular ferrite is reduced in plastically deformed austenite, which is a characteristic of a displacive transformation mechanism. The increase in the chemical driving force for transformation due to large undercooling below the B-s temperature overcomes the efficacy of dislocations in preventing the growth of acicular ferrite. (C) 2003 Elsevier B.V. All rights reserved.