Steel for 90kg-level high-strength round-link chain and smelting process of steel

The invention provides steel for a 90kg-level high-strength round-link chain and a smelting process of the steel. The steel for the 90kg-level high-strength round-link chain is prepared from, by weight percent, 0.17%-0.25% of carbon, 0.15%-0.35% of silicon, 0.90%-1.30% of Mn, not larger than 0.025% of phosphorus, not larger than 0.025% of sulfur, 0.40%-0.70% of Cr, 0.30%-0.70% of Ni, 0.020%-0.060% of Al and the balance Fe and inevitable impurities. The smelting process of the steel comprises the steps that a 150mm*150mm casting blank is obtained according to conventional converter smelting, LF refining and continuous casting, and coil rods of different specifications are obtained through a high-speed wire mill in a rolling manner. The steel of the 90kg-level high-strength round-link chain obtained in this manner is high in molten steel purity degree and strength and good in toughness and has good mechanical performance. The steel is reasonable in ingredient design, low in production cost, high in molten steel purity degree, good in product performance and convenient to widely apply and popularize. The smelting process is simple, the casting blank is rolled into the coil rods of different specifications through the high-speed wire mill, the strength of the round-link chain obtained after annealing, drawing, chaining and heat treatment can reach 90 kg, and higher hardness and wear resistance are achieved.