Abstract: A method of hot forming hybrid parts wherein side-by-side with a thin-walled piece of steel stock, which has been heated to austenite temperature, another piece of stock of another formable metal is placed, The processing temperature of this formable metal corresponds to the temperature at which quenching of the steel stock is interrupted within an interval between the Ms and Mf temperatures. The steel stock and formable metal are then formed together, while the temperature decreases to a temperature which is close to the forming tool temperature. Next, the resulting semi-finished product is cooled to the ambient temperature.

Abstract: In a first step of the method of achieving TRIP microstructure in steels by deformation heat, steel feedstock is heated to a temperature below the temperature at which austenite begins to form in the steel in question, i.e. below AC1. In a next step, the feedstock is formed into a final product, using applied severe plastic deformation whereby deformation energy causes the temperature of the material to increase to the final temperature between AC1 and AC3, and whereupon the ferrite-pearlite microstructure transforms into austenite. In a third or last process step, the final product is cooled down from the final temperature to the temperature of the bainite nose of the material (B). The cooling is then interrupted and the material is held at the temperature of the bainite nose (B). Consequently, the TRIP microstructure forms. Finally, the product is cooled down to ambient temperature.

Abstract: A method of production of high-strength hollow bodies from multiphase martensitic steels includes a heating process, a forming process and a cooling process. A heating device heats hollow steel stock to the austenitic temperature of the material from which the stock is made. The stock is then converted by deformation in a forming device into a hollow body having the final shape. A cooling device thereafter cools the hollow body such that the material with the original austenite microstructure refined by deformation during the forming process cools to a temperature at which incomplete transformation of austenite to martensite occurs. The retained austenite stabilization is performed in an annealing device by diffusion-based carbon partitioning within the material from which the hollow body is made. The hollow body is cooled in a cooling device to ambient temperature after stabilization.