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CN-121992278-A - Smelting method for replacing ferrocolumbium with ferrotitanium for HRB600 steel

CN121992278ACN 121992278 ACN121992278 ACN 121992278ACN-121992278-A

Abstract

The invention belongs to the technical field of ferrous metallurgy, and particularly discloses a smelting method for HRB600 steel by using ferrotitanium instead of ferroniobium, which comprises the steps of pouring molten iron into a converter for smelting, sequentially adding ferrosilicon, ferrosilicon and vanadium nitrogen for alloying, then performing bottom blowing argon smelting, adding ferrosilicon, ferrosilicon and vanadium nitrogen according to argon station components for alloy fine tuning to an internal control component range, smelting a ladle to a refining furnace after argon blowing is completed, adding ferrotitanium according to final sample Ti components, feeding wires for soft blowing after the refining furnace is finished, and casting the ladle after the soft blowing is finished for more than or equal to 5.5 minutes. Aiming at the problems of larger addition amount and higher cost of vanadium-nitrogen alloy and niobium-iron alloy in the production process of HRB600 steel. The invention uses low-cost ferrotitanium to replace ferroniobium through converter smelting, refining furnace adjustment, ferrotitanium addition, continuous casting and control of key parameters, and reduces production cost on the premise of ensuring mechanical properties of steel.

Inventors

  • XU JIANFEI
  • LIU WANGPING
  • MA JINGUO

Assignees

  • 新疆伊犁钢铁有限责任公司

Dates

Publication Date
20260508
Application Date
20251224

Claims (7)

  1. 1. A smelting method for replacing ferroniobium with ferrotitanium for HRB600 steel is characterized by comprising the following steps: S1, pouring molten iron into a converter for smelting, controlling the end point [ C ] of the converter to be 0.07% -0.16%, controlling the end point [ P ] to be less than or equal to 0.025%, and controlling the tapping temperature to be 1640 ℃ -1680 ℃, sequentially adding silicon-manganese alloy, silicon iron and vanadium nitrogen for alloying in the tapping process, wherein all the alloys are added when tapping is performed by 1/3, and the alloys are completely added when tapping is performed by 3/4; S2, after the molten steel arrives at a station, turning a ladle car to a smelting station for power transmission smelting, adding lime, a slag melting agent and a composite deoxidizer for slag formation, and adding silicon-manganese alloy, silicon iron and vanadium nitrogen according to the components of an argon station for alloy fine adjustment to be within the range of internal control components; S3, hoisting the ladle to a refining furnace for smelting after argon blowing is completed, sampling the end point of the refining furnace, supplementing ferrotitanium according to the finally spotted Ti component, and supplementing the Ti component to 0.014% -0.020%; S4, feeding wires for soft blowing after smelting in a refining furnace, wherein the soft blowing time is more than or equal to 5.5 minutes, standing for 2-3 minutes after soft blowing is finished, and hanging the ladle to a continuous casting ladle turret; S5, the continuous casting ladle turret is rotated to a pouring box casting position, a ladle slide plate is pulled open, and molten steel is placed into the pouring box for casting.
  2. 2. The smelting method for replacing ferroniobium with ferrotitanium for HRB600 steel according to claim 1, wherein in S1, a composite deoxidizer is added according to the condition of end point control during tapping, the adding amount of each batch is controlled to be 13kg, the interval time is more than 5 seconds, and the ton of steel of the composite deoxidizer is controlled to be 1.0-1.5 kg/t.
  3. 3. The smelting method of HRB600 steel using ferrotitanium to replace ferroniobium according to claim 1, wherein in S5, the casting powder is dry low-carbon hollow pre-dissolved granular slag in the continuous casting process, the casting powder is baked before being used, the casting section is 150mm multiplied by 150mm, and the billet sizing is 8500-12000 mm.
  4. 4. The smelting method for replacing ferroniobium with ferrotitanium for HRB600 steel according to claim 1, wherein in S5, liquidus temperature is 1498 ℃, tundish baking temperature is 1100-1250 ℃, start-up furnace ladle molten steel target temperature is 1610-1640 ℃, tundish molten steel target temperature is >1560 ℃, continuous casting furnace ladle molten steel target temperature is 1610-1640 ℃, and tundish molten steel target temperature is 1520-1530 ℃.
  5. 5. The smelting method for replacing ferroniobium with ferrotitanium for HRB600 steel according to claim 1, wherein in S5, the water distribution mode of continuous casting is that the flow of a crystallizer is 2000-2100L/min, the pressure of secondary cooling air of each secondary cooling section is 0.23-0.30 MPa, and when the pulling speed is lower than 2.0m/min, the pressure of secondary cooling air is 0.15-0.20 MPa.
  6. 6. The smelting method for replacing ferroniobium with ferrotitanium for HRB600 steel according to claim 1, wherein in S5, the temperature and the pulling speed are controlled in such a way that the pulling speed is less than or equal to 1.8m/min when the temperature is more than or equal to 1550 ℃, the pulling speed is 1.8-2.4 m/min when the temperature is 1540-1550 ℃, the pulling speed is 2.4-2.8 m/min when the temperature is 1530-1540 ℃, the pulling speed is 2.8-3.3 m/min when the temperature is 1520-1530 ℃, and the pulling speed is more than or equal to 3.3m/min when the temperature is <1520 ℃.
  7. 7. The smelting method for replacing ferroniobium with ferrotitanium for HRB600 steel according to claim 6, wherein the pulling speed is adjusted to be 0-0.4 m/min when the production is abnormal, and the pulling speed is reduced by 0.2-0.4 m/min when S in molten steel is more than or equal to 0.035%.

Description

Smelting method for replacing ferrocolumbium with ferrotitanium for HRB600 steel Technical Field The invention relates to the technical field of ferrous metallurgy, in particular to a smelting method for replacing ferroniobium with ferrotitanium for HRB600 steel. Background The HRB600 high-strength twisted steel is used as a high-performance steel bar of the smelting method of replacing ferroniobium by ferrotitanium, and is widely used in industrial and civil buildings, railways, bridges, roads and other industrial construction projects by excellent physical properties and chemical components, in the production process of the HRB600 high-strength twisted steel, a certain amount of ferrosilicon alloy and ferrosilicon alloy are added into molten steel, and a certain amount of alloy containing vanadium (V) and niobium (Nb) is added for microalloying process, so that the performance of the produced product can meet the national standard requirements. At present, most iron and steel enterprises widely use vanadium nitrogen and niobium iron with lower cost as microalloying alloy in the production process of HRB600 high-strength twisted steel. With the rising price of steel, the vanadium-nitrogen-niobium-iron alloy for high-strength threaded steel has a continuous rising price trend, and under the condition that the production profit of the current steel is lower, all steel enterprises are searching for ways for reducing the alloy cost, and how to develop a substitute additive which can meet the national standard requirements and reduce the production cost of the HRB600 high-strength threaded steel is an important problem faced by all large steel enterprises. At present, adding vanadium-nitrogen alloy and niobium-iron alloy into a steel ladle for microalloying in the production process of HRB600 high-strength screw steel is the first choice process of each iron and steel enterprise. The process method mainly comprises the steps of adding vanadium-nitrogen alloy and niobium-iron alloy into molten steel, refining steel grains and increasing toughness by utilizing V component in the vanadium-nitrogen alloy, forming continuous solid solution by vanadium and iron, strongly reducing austenite phase region, thereby improving physicochemical property of the steel, forming niobium carbonitride precipitated phase in the steel by utilizing niobium to prevent growth of austenite grains, realizing grain refinement, preventing dislocation movement by precipitated niobium carbonitride particles, improving strength of the steel, promoting transformation of ferrite to pearlite, and improving internal structure. The vanadium-nitrogen alloy and the niobium-iron alloy are added in a larger amount in the production process of the HRB600 high-strength twisted steel, and the vanadium-nitrogen alloy and the niobium-iron alloy are higher in price, so that the microalloying smelting cost is higher by adding the vanadium-nitrogen alloy and the niobium-iron alloy in the production process of the HRB600 high-strength twisted steel. Disclosure of Invention The invention aims to provide a smelting method for replacing ferrotitanium with ferrotitanium for HRB600 steel, which aims to solve the problems of higher production cost caused by higher addition amount of vanadium-nitrogen alloy and ferroniobium alloy and higher price in the production process of HRB600 high-strength threaded steel. In order to achieve the aim, the basic scheme provided by the invention is that a smelting method for replacing ferroniobium with ferrotitanium for HRB600 steel comprises the following steps: S1, pouring molten iron into a converter for smelting, controlling the end point [ C ] of the converter to be 0.07% -0.16%, controlling the end point [ P ] to be less than or equal to 0.025%, and controlling the tapping temperature to be 1640 ℃ -1680 ℃, sequentially adding silicon-manganese alloy, silicon iron and vanadium nitrogen for alloying in the tapping process, wherein all the alloys are added when tapping is performed by 1/3, and the alloys are completely added when tapping is performed by 3/4; S2, after the molten steel arrives at a station, turning a ladle car to a smelting station for power transmission smelting, adding lime, a slag melting agent and a composite deoxidizer for slag formation, and adding silicon-manganese alloy, silicon iron and vanadium nitrogen according to the components of an argon station for alloy fine adjustment to be within the range of internal control components; S3, hoisting the ladle to a refining furnace for smelting after argon blowing is completed, sampling the end point of the refining furnace, supplementing ferrotitanium according to the finally spotted Ti component, and supplementing the Ti component to 0.014% -0.020%; S4, feeding wires for soft blowing after smelting in a refining furnace, wherein the soft blowing time is more than or equal to 5.5 minutes, standing for 2-3 minutes after soft blowing is finished, and hanging th