METHOD FOR PRESSWORK OF HIGH-STRENGTH IRON PRODUCTS Russian patent published in 2019 - IPC B21J5/02 C21D8/00 

FIELD: technological processes.

SUBSTANCE: invention relates to the processing of metals by pressure and can be used for presswork of high-strength cast iron products. Billet is heated to a temperature T₁ and deformed in the press. Produce monotonous cooling of the workpiece with a temperature T₁ up to temperature T₂ in the process of plastic deformation and temperature T₂ up to temperature T₃ upon completion of plastic deformation while maintaining the pressure in the die below the yield strength of high-strength cast iron. Then, while maintaining the specified pressure, the workpiece is continuously cooled to a temperature T₄ with speed V_o and further to temperature T_5. Comply with the following conditions: 950 °C<T₁<T_S; 950 °C≤T₂<T_S; T_Ap≤T₃<950 °C; V_o>V_cr; T₄≤T_Mo; T₅≤T_Me, where T_S – solidus high-strength iron temperature; T_Ap – temperature of onset of austenitic-perlite transformations in high-strength cast iron; V_cr – critical cooling rate – the minimum rate at which the diffusion-free transformation of austenite into martensite occurs; T_Mo – temperature of the onset of phase transformations of austenite to martensite in high-strength cast iron; T_Me – temperature of the end of phase transformations of austenite to martensite in high-strength cast iron.

EFFECT: result is an expansion of the technological capabilities of the method.

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