High-strength steel based on direct quenching process and method for manufacturing same

Abstract

The application provides a high-strength steel based on a direct quenching process, which contains the following chemical elements in percentage by mass: C: 0.06-0.20%, Si: 0.05-0.30%, Mn: 0.5-1.8%, Cr: 0.1-0.8%, Ti: 0.10-0.20%, Al: 0.015-0.06%, Ca: 0.001-0.004%, and N≤0.005%. The application also provides a preparation method of the high-strength steel, which comprises the following steps: heating a slab, rough rolling, finish rolling, and online quenching treatment, wherein the cooling rate is greater than or equal to 100 DEG C / s, and the final cooling temperature is less than or equal to (Ms-150) DEG C; and then carrying out coiling, water blowing treatment, and tempering heat treatment. On the basis of low alloy cost, the high-strength steel has a longitudinal yield strength of 900-1050 MPa, a tensile strength of 950-1200 MPa, an elongation rate of greater than or equal to 14%, and good plate shape.

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