Tire cord steel with high strength and low wire breakage rate, and rolling method and use thereof

A method for rolling tire cord steel, comprising:

• obtaining a steel billet;
• and
• sequentially performing a heating-before-rolling, a hot-rolling and a cooling-after-rolling on the steel billet to obtain a wire rod of the tire cord steel;
• wherein the heating-before-rolling comprises a preheating stage, a first heating stage, a second heating stage and a soaking stage, and
• the hot-rolling adopts an austenite crystallization controlled-rolling and the hot-rolling sequentially comprises a rough rolling, an intermediate rolling, a pre-finish rolling, a finish rolling, and a sizing and reducing;
• wherein a preheating temperature of the preheating stage is ≤400° C., and a preheating time of the preheating stage is ≥5 min;
• a terminal temperature of heating temperature of the first heating stage is between 400° C.-800° C., and a heating time of the first heating stage is ≥10 min;
• a terminal temperature of heating temperature of the second heating stage is between 800° C.-1000° C., and a heating time of the second heating stage is between 60 min-100 min;
• and
• a soaking temperature of the soaking stage is 1000° C.-1040° C., and a soaking time of the soaking stage is 20 min-60 min;
• wherein chemical compositions by mass fraction of the tire cord steel comprises:
• C:
• 0.80%-0.85%, Mn:
• 0.46%-0.59%, Nb:
• 0.006%-0.012%, V:
• 0.006%-0.012%, Si:
• 0.15%-0.25%, P:
• ≤0.01%, S:
• ≤0.01%, B:
• 0.0005%-0.0009%, Als:
• ≤0.0008%, Ti:
• ≤0.0005%, Fe and inevitable impurities;
• wherein the chemical compositions of the tire cord steel further comprise N, wherein ([Nb]+ [V])/[N] is between 3-4.5, and wherein the [Nb] represents a mass fraction of Nb element, the [V] represents a mass fraction of V element, and the [N] represents a mass fraction of N element.