Microstructure and Mechanical Properties of Acicular Ferrite Steel

The morphology of acicular ferrite is composed of an assemblage of interwoven nonparallel ferrite laths with a fairly high dislocation denity under TEM.Techniques of in situ tension under SEM and TEM were used to study the process of plastic deformation and cracking in F40 ship plate.Study was made on F40 about fracture morphology of impact fracture in low temprature.Experimental results showed that acicular ferrite can resist plastic deformation and deter crack expansion effectively.