Production method of large-size high-strength high-toughness mooring chain

The invention discloses a production method of a large-size high-strength high-toughness mooring chain. The production method comprises the working procedures of converter treatment, LF refining, VD refining, continuous casting, slow cooling, hot rolling and heat treatment. In the LF refining process, lime and refining slag are supplemented when LF refining is in place, the using amount of the lime in the refining process is 8-12 kg/t steel, the using amount of the refining slag in the refining process is 18-22 kg/t steel, the refining time is 60-80 min, and the maintaining time of the white slag is 25-35 min; in the LF refining process, the use amount of silicon carbide is 3-6 kg per ton of steel, the use amount of aluminum particles is 0.5-1.0 kg per ton of steel, and the alkalinity is controlled to be 5-8. According to the mooring chain produced through the method, the tensile strength is larger than 980 MPa, the yield strength is larger than 880 MPa, the percentage elongation after fracture is larger than