Hot-rolled steel sheet and its preparation method and application

The invention relates to the field of hot-rolled steel sheet production, and specifically discloses a hot-rolled steel sheet and a preparation method and application thereof. The microstructure of the hot-rolled steel sheet is an austenite structure and a martensitic structure. The content of morphological austenite structure accounts for more than 20% of the total austenite structure content. The preparation method of the hot-rolled steel sheet provided by the present invention comprises the following steps: heating, rough rolling, finishing rolling and solid solution of the slab formed by forging in sequence; The deformation rate of the finishing rolling is 60-70%, and the deformation rate of the final pass deformation of the finishing rolling is 8-12%. The invention adopts a new controlled rolling process, so that the hot-rolled steel plate has high strength, high plasticity and high toughness at normal temperature, and also has good low temperature and ultra-low temperature properties, and is especially suitable for application in rocket engines.