Heredity of hot rolled microstructure in a high strength TRIP steel

The influence of hot rolling process on microstructure and mechanical property of a TRIP steel,and the heredity of the microstructure and property in the hot rolled TRIP steel after annealing was investigated.The results show that coiling temperature is the key factor for microstructure and mechanical property of the hot rolled steel,and two different kinds of microstructure are obtained under different coiling temperatures,one is composed of ferrite,pearlite and bainite,and the other consists of ferrite,bainite and austenite.After annealing,the grains of the first kind of hot rolling microstructure are greatly refined,and mechanical properties of the hot rolled TRIP steel are evidently improved,and the fraction of austenite and its carbon content are also increased significantly,and no heredity of the microstructure is observed.However,little changes in grain size,mechanical properties,fraction and carbon content of retained austenite for the TRIP steel with the second kind of hot rolling microstructure after annealing treatment are detected,exhibiting obvious heredity of microstructure.