CN-121983184-A - Control method for magnesium content in high-carbon steel and application thereof

Abstract

The invention provides a control method for magnesium content in high-carbon steel and application thereof, and relates to the field of metal casting. According to the control method, specific parameter design regulation and control are carried out by applying Thermo-Calc software, the magnesium content in the system is set to exceed the saturation value of the magnesium content in the system, and the optimal range value of the magnesium content in the high-carbon steel is obtained through calculation and high-carbon steel tensile property test, so that the accurate control of the magnesium content in the high-carbon steel is realized. The control method is simple and easy to operate, high in accuracy and suitable for large-area application and popularization. The control method for the magnesium content in the high-carbon steel is applied to the smelting process of the high-carbon steel, can improve the comprehensive mechanical properties of steel products, and can avoid defects.

Inventors

• XU GUANG
• DENG ZHIXUN
• ZENG BIN
• DAI ZHICAI
• NIE CHANGPING
• HOU ZEWANG
• LI ZOUJIANG
• LIANG LIANG
• WAN XUEFENG
• LIU XUHUI
• QI JIANGHUA
• LIU NING
• WEN CHANGFEI
• LIU PENG
• XIE SHIZHENG

Assignees

• 湖南华菱涟钢特种新材料有限公司
• 湖南华菱涟源钢铁有限公司

Dates

Publication Date

20260505

Application Date

20251127

Claims (10)

1. 1. The control method for the magnesium content in the high-carbon steel is characterized by comprising the following steps: Providing a steel chemical composition data set, wherein in the steel chemical composition data set, 0.80-0.82% of C, 0.18-0.22% of Si, 0.38-0.42% of Mn, 0.3-0.34% of Cr, 1.5-1.7% of Ni, 0-0.01% of P, 0-0.005% of S, 0.04-0.045% of Al, 0-0.001% of O, x% of Mg, and the balance of Fe and other unavoidable impurity elements in parts by mass, wherein x is larger than the saturation value of Mg in a system; Adopting Thermo-Calc software, selecting TCFE9: steels/Fe-alloy v9.0 database, inputting chemical composition data set of the steel, adopting supersaturation calculation method, setting cooling interval from 1600 ℃ to 600 ℃ and obtaining the temperature-dependent curve of each phase of magnesium solubility in the cooling phase change process; Selecting the sum of the magnesium solubility of each phase except the magnesium liquid phase as the upper limit value (Mg max ) of the magnesium content in the high-carbon steel when the magnesium content of the magnesium liquid phase is maximum in the cooling phase change process in a temperature change curve of each phase of the magnesium solubility in the cooling phase change process, and selecting the magnesium element addition of the high-carbon steel which meets the requirements of tensile strength of more than or equal to 1500MPa, yield strength of more than or equal to 1350MPa, elongation after fracture of more than or equal to 9 percent and reduction of area of more than or equal to 22 percent in the high-carbon steel tensile property test experiment as the lower limit value (Mg min ) of the magnesium content in the high-carbon steel; Controlling the magnesium content in the high carbon steel to be from the Mg min to the Mg max .
2. 2. The method for controlling the magnesium content in high-carbon steel according to claim 1, wherein the upper limit value of the magnesium content in the high-carbon steel is the sum of the solubility of magnesium in the beneficial precipitation phases, and the beneficial precipitation phases comprise MgC 2 .
3. 3. The method for controlling magnesium content in high carbon steel according to claim 1, wherein the pressure of the Thermo-Calc software is set to normal pressure.
4. 4. Use of the method for controlling magnesium content in high carbon steel according to any one of claims 1 to 3 in a high carbon steel smelting process, comprising the steps of: Sequentially carrying out vacuum pressurizing furnace smelting treatment, magnesium treatment, die casting treatment, spheroidizing annealing treatment, quenching treatment and tempering treatment on molten steel; the magnesium treatment mode is to add magnesium alloy into the molten steel after the smelting treatment of the vacuum pressurizing furnace until the magnesium content in the target molten steel is the magnesium content in the high-carbon steel according to any one of claims 1-3.
5. 5. The use according to claim 4, wherein in the magnesium treatment, the magnesium content in the target molten steel is 0.08% -0.27%.
6. 6. The use according to claim 4, wherein in the magnesium treatment, the magnesium content in the target molten steel is 0.20% -0.27%.
7. 7. The use according to claim 4, characterized in that the tapping temperature of the vacuum pressure furnace smelting treatment is 1570-1600 ℃.
8. 8. The use according to claim 4, wherein the spheroidizing annealing treatment is isothermal spheroidization.
9. 9. The use according to claim 8, wherein the first stage temperature of isothermal spheroidization is 1000-1050 ℃, the first stage time of isothermal spheroidization is 10-15 min, the second stage temperature of isothermal spheroidization is 900-950 ℃, and the second stage time of isothermal spheroidization is 2-3 h.
10. 10. The use according to claim 4, wherein the quenching treatment is carried out at a temperature of 1080-1110 ℃ and the tempering treatment is carried out at a temperature of 680-720 ℃.

Description

Control method for magnesium content in high-carbon steel and application thereof Technical Field The invention relates to the field of metal casting, in particular to a control method for magnesium content in high-carbon steel and application thereof. Background With the continuous progress of steel production technology, magnesium treatment becomes an important method for improving performance and saving precious alloy. It is conventionally considered that a higher content of added magnesium in the smelting process can give a steel product of better quality. However, in the production process, the quality of the steel product is not gradually improved along with the increase of the magnesium content, and even if the magnesium content in the steel is excessive, cracks can be generated in the steel product. In the prior art, the magnesium content in steel is controlled to be 0.001% -0.005% (10-50 ppm) by adopting a wire-feeding fire alloy additive method, so that harmful inclusions can be effectively controlled, but the further improvement of the performance of steel products is limited. Disclosure of Invention The invention mainly aims to provide a control method for the magnesium content in high-carbon steel and application thereof, and aims to solve the problems that the magnesium content in the high-carbon steel is difficult to accurately control, the obtained high-carbon steel has grain boundary defects or has lower performance and the like in the prior art. In order to achieve the above object, the present invention provides a method for controlling magnesium content in high carbon steel, comprising the steps of: A chemical composition data set of steel is provided, wherein in the chemical composition data set of steel, 0.80% -0.82% of C, 0.18% -0.22% of Si, 0.38% -0.42% of Mn, 0.3% -0.34% of Cr, 1.5% -1.7% of Ni, 0% -0.01% of P, 0% -0.005% of S, 0.04% -0.045% of Al, 0% -0.001% of O, x% of Mg, and the balance of Fe and other unavoidable impurity elements are calculated according to mass parts, and x is larger than the saturation value of Mg in a system. And adopting Thermo-Calc software, selecting a TCFE9: steels/Fe-alloy v9.0 database, inputting a chemical composition data set of the steel, adopting a supersaturation calculation method, setting a cooling interval from 1600 ℃ to 600 ℃ and obtaining a temperature-dependent change curve of the solubility of magnesium of each phase in the cooling phase change process. And selecting the sum of the magnesium solubility of each phase except the magnesium liquid phase as the upper limit value (Mg max) of the magnesium content in the high-carbon steel when the magnesium content of the magnesium liquid phase is maximum in the cooling phase change process in the temperature change curve of each phase of the magnesium solubility, and selecting the magnesium element addition of the high-carbon steel which meets the requirements of tensile strength of more than or equal to 1500MPa, yield strength of more than or equal to 1350MPa, elongation after fracture of more than or equal to 9 percent and reduction of area of more than or equal to 22 percent in the high-carbon steel tensile property test experiment as the lower limit value (Mg min) of the magnesium content in the high-carbon steel. Controlling the magnesium content in the high carbon steel to be from the Mg min to the Mg max. Further, the upper limit value of the magnesium content in the high-carbon steel is the sum of the solubility of magnesium in the beneficial precipitation phases, and the beneficial precipitation phases comprise MgC 2. Further, the pressure of the Thermo-Calc software is set to be normal pressure. The invention also provides an application of the control method for the magnesium content in the high-carbon steel in the smelting process of the high-carbon steel, which comprises the following steps: the molten steel is sequentially subjected to vacuum pressurizing furnace smelting treatment, magnesium treatment, die casting treatment, spheroidizing annealing treatment, quenching treatment and tempering treatment. The magnesium treatment mode is to add magnesium alloy into the molten steel after the smelting treatment of the vacuum pressurizing furnace until the magnesium content in the target molten steel is the magnesium content in the high-carbon steel according to any one of the above. Further, in the magnesium treatment, the magnesium content in the target molten steel is 0.08% -0.27%. Further, in the magnesium treatment, the magnesium content in the target molten steel is 0.20% -0.27%. Further, the tapping temperature of the vacuum pressurizing furnace smelting treatment is 1570-1600 ℃. Further, the spheroidizing annealing treatment is isothermal spheroidizing. Further, the temperature of the first stage of isothermal spheroidization is 1000-1050 ℃, the duration of the first stage of isothermal spheroidization is 10-15 min, the temperature of the second stage of isothermal spheroidizat