Discontinuous twinning during essentially elastic compression of steel at 4·2°K

Abstract

The extended stress—strain behaviour of SAE 1010 steel has been observed by compression testing at 4·2°k, far below the tensile ductile-brittle transition temperature. The permanent deformation is totally taken up by discontinuous load-drops in the force/displacement curve, otherwise the specimen shows continued elastic loading. These results are attributed to essentially elastic twinning of the steel whereby the twins and accommodating matrix flow produce a ‘locked-in’ state of deformation.