The invention relates to a 1500MPa-grade high-strength
tool steel wire rod and a manufacturing method thereof.The method includes the steps that after Nb-V chemical component design is adopted for rolling and
spinning to form a
wire rod, online
molten salt subcooling quenching isothermal treatment is conducted,
molten salt of the
wire rod at the front section is controlled to enter a
martensite phase region from a high-temperature
austenite state at the
cooling speed larger than or equal to 37 DEG C / s, part of
austenite is promoted to be converted into a
martensite structure, and then the steel wire rod is rolled and spun; the method comprises the following steps of: heating to a sorbite phase region through a rear-section
molten salt, promoting the transformation of
austenite residues to a sorbite structure, carrying out isothermal
tempering toughening destressing treatment on the structure, and finally slowly cooling through a roller way to prepare a wire rod of which the microscopic structure comprises tempered sorbite and tempered
martensite, the material cost can be properly controlled, the
phase change of the wire rod is powerfully regulated and controlled, the strength and
plasticity matching of the wire rod is improved, the tensile strength is 1470-1520 MPa, and the
percentage reduction of area is 52%-57%, so that additional heat treatment after cold
machining is omitted, the production
energy consumption and cost of the
tool steel are reduced, and the efficiency is improved.