Production method of hot rolled ribbed steel bar

Abstract

The invention relates to a production method of a hot rolled ribbed steel bar. The size of a spring steel hot rolled wire rod ranges from [phi]8mm to [phi] 10mm; and steel comprises the chemical components in percentage by mass: 0.20 percent to 0.25 percent of C, 0.40 percent to 0.50 percent of Si, 1.40 percent to 1.60 percent of Mn, less than or equal to 0.045 percent of P, less than or equal to0.045 percent of S, 0.015 percent to 0.020 percent of V, and the balance Fe and inevitable impurity elements. A rolling technology is characterized in that the tapping temperature ranges from 1070 to1130 DEG C, the temperature for entering pre-finish rolling ranges from 970 to 1000 DEG C, and the temperature for entering finish rolling ranges from 840 to 880 DEG C; the laying temperature ranges from 845 to 875 DEG C; the finish rolling temperature is the recrystallization temperature or less at an austenitic area; quick cooling is carried out on an air cooling roller through a fan, and the air volume is 100 percent; and heat preservation is carried out through closing a roller way of a heat-preservation cover, the temperature for entering the heat-preservation cover ranges from 640 to 660DEG C, the temperature for exiting from the heat-preservation cover ranges from 600 to 620 DEG C, and the time for staying in the heat-preservation cover ranges from 45 to 55s. According to the production method of the hot rolled ribbed steel bar provided by the invention, through adding a small amount of V alloy and finish rolling unit low-temperature rolling, the stable operation of equipment is ensured, the alloy content is further reduced, and the cost is reduced.

Description

technical field [0001] The invention relates to the technical field of metal material processing and forming, and relates to a production method of hot-rolled ribbed steel bars, in particular to a production method of HRB400E coiled snails with a height of Φ8 mm to Φ10 mm. Background technique [0002] In the current rebar market, HRB400E accounts for the majority. The microalloy strengthening method is the main way to produce HRB400E internationally. The microalloys are mainly vanadium alloys or niobium alloys, which consume a large amount of alloy resources every year. Due to limited mineral resources containing vanadium and niobium elements, the supply of these alloying elements is tight. Therefore, if the alloy content of HRB400E steel bars can be reduced, it will produce huge economic and social benefits. [0003] In the current prior art, a double-strand rolling production line without a reducing and sizing mill generally adopts vanadium alloy strengthening to produc...

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Problems solved by technology

[0004] Chinese patent CN104357741A discloses a HRB400E high-strength anti-seismic steel bar screw and its production method. This method includes a reduction and sizing rolling mill to produce finished products, which can ensure that the finished rolled steel parts are rolled at a low temperature of 730~760°C to obtain Finer grains, this method is not suitable for production lines without reducing and sizing mills

Chinese patent CN110184516 A discloses a method for preparing high-wire φ6mm~HRB400E coiled snails. With the help of the strong rolling capacity of the equipment, low-temperature rolling is started from the heating temperature, and the production without adding microalloys is realized. The disadvantages of this method It has high requirements on the strength and motor performance of the roughing and medium rolling equipment, especially for the torsion rolling production line, which reduces the experimental life of the equipment and increases the maintenance cost of the equipment, and the yield strength of the high wire φ6mm~HRB400E disc screw produced by this method Insufficient margin, it is difficult to guarantee the qualified rate of performance

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