METHOD FOR OBTAINING STEEL PART WITH MULTIPLE-PHASE MICROSTRUCTURE Russian patent published in 2010 - IPC C21D1/18 C21D1/673 C21D7/13 C22C38/58 C22C38/38 C22C38/50 C22C38/28 C23C2/26 

FIELD: metallurgy.

SUBSTANCE: invention refers to metallurgy industry, and namely to the part made from steel and having multiple-phase microstructure. Ingot is cut from steel bar, which includes the following, wt %: 0.01 ≤ C ≤ 0.50, 0.50 ≤ Mn ≤ 3.0, 0.001 ≤ Si ≤ 3.0, 0.005 ≤ Al ≤ 3.0, Mo ≤ 1.0, Cr ≤ 1.5, P ≤ 0.10, Ti ≤ 0.20, V ≤ 1.0, if necessary, one or several elements from Ni ≤ 2.0, Cu ≤ 2.0, S ≤ 0.05, Nb ≤ 0.15, the rest is iron and impurities appeared as a result of melting process. Cold pre-deformation of the above ingot is performed if necessary. Ingot is heated so that soaking temperature T_s higher than Ac1 point but not less than Ac3 can be reached, and is soaked at this temperature during soaking time t_s to provide austenite content in steel, which is equal to or more than 25% along the horizontal, after ingot is heated. The above heated ingot is put to hot forming device so that a part is produced. Part is cooled in this device at V cooling speed so that steel microstructure is multiple-phase microstructure including ferrite and homogeneous in each area of the above part.

EFFECT: there is proposed manufacturing method of part from steel, which has multiple-phase structure.

19 cl, 1 dwg, 4 tbl