A phenomenon, occurring chiefly in certain highly alloyed steels that have been heat treated to
produce metastable austenite or metastable austenite plus martensite, whereby, on subsequent
deformation, part of the austenite undergoes strain-induced transformation to martensite. Steels
capable of transforming in this manner, commonly referred to as TRIP steels, are highly plastic
after heat treatment, but exhibit a very high rate of strain hardening and thus have high tensile
and yield strengths after plastic deformation at temperatures between about 20 and 500 °C (70
and 930 °F). Cooling to -195 °C (-320 °F) may or may not be required to complete the
transformation to martensite. Tempering usually is done following transformation.