CN-121992170-A - Method for controlling titanium element of high-titanium welding wire steel

CN121992170ACN 121992170 ACN121992170 ACN 121992170ACN-121992170-A

Abstract

The invention belongs to the technical field of high-titanium welding wire steel, and relates to a method for controlling titanium element of high-titanium welding wire steel, which is produced according to target components of high-titanium welding wire steel through the procedures of converter or electric furnace smelting, LF refining and continuous casting in sequence, wherein when steel is tapped in the smelting procedure, ferrosilicon with equal silicon mass is added according to the target silicon component mass of 90% of high-titanium welding wire steel, medium-carbon ferromanganese with equal manganese mass is added according to the total amount of the target manganese component of 90% of high-titanium welding wire steel, after deoxidation is completed in the refining procedure, the (FeO+MnO) content in refined slag is controlled below 1.0%, then titanium element fine adjustment is carried out by feeding a low-aluminum low-nitrogen ferrotitanium wire through a wire feeder, the titanium content in molten steel is controlled within a target range, and simultaneously the aluminum and nitrogen content in molten steel is controlled within a steel type requirement range, and the continuous casting procedure adopts a whole-process protection casting technology to prevent titanium content loss caused by secondary oxidization of molten steel.

Inventors

LI SHANGBING
CHEN YUANQING
HOU XINGHUI
GUO FENG
SONG WANPING
LI CHENGBIN
LI XIAOPAN
MA ZHIJUN

Assignees

江苏永钢集团有限公司
联峰钢铁（张家港）有限公司

Dates

Publication Date: 20260508
Application Date: 20260127

Claims (10)

1. A method for controlling titanium element of high-titanium welding wire steel is characterized in that according to target components of the high-titanium welding wire steel, the steelmaking production process sequentially comprises the working procedures of converter or electric furnace smelting, LF refining and continuous casting, wherein: When tapping in the converter or electric furnace smelting process, adding ferrosilicon alloy with equal silicon mass according to the mass of 90% of target silicon components of the high-titanium welding wire steel, and adding medium-carbon ferromanganese with equal manganese mass according to the total mass of 90% of target manganese components of the high-titanium welding wire steel; After the LF refining process adopts silicon carbide and calcium carbide to deoxidize completely, controlling the (FeO+MnO) content in refining slag to be below 1.0%, and then feeding a low-aluminum low-nitrogen ferrotitanium wire to perform titanium element fine adjustment through a wire feeder, controlling the titanium content in molten steel to be within a target range, and simultaneously controlling the aluminum and nitrogen content in the molten steel to be within a steel grade requirement range; The continuous casting process adopts a whole-course protection casting process to prevent the loss of titanium content caused by secondary oxidation of molten steel.
2. The method for controlling the titanium element in the high-titanium welding wire steel according to claim 1, wherein the fine adjustment of the titanium element is controlled through the wire feeding speed and the wire feeding quantity of a wire feeding machine, the wire feeding speed is 150-200m/min, the wire feeding angle is perpendicular to the liquid level of molten steel, and the wire feeding quantity is more than 80% of the titanium yield in the low-nitrogen low-aluminum titanium iron wire.
3. The method for controlling the titanium element in the steel of the high-titanium welding wire, which is characterized in that the low-aluminum low-nitrogen ferrotitanium wire is formed by crushing low-aluminum low-nitrogen ferrotitanium alloy to low-aluminum low-nitrogen ferrotitanium alloy powder smaller than 2mm by adopting a jaw crusher and a pair roller, and then winding the low-aluminum low-nitrogen ferrotitanium alloy powder and a steel belt into a cored wire by using a cored wire machine.
4. The method for controlling the titanium element of the high-titanium welding wire steel, as claimed in claim 3, wherein the preparation method of the low-aluminum low-nitrogen ferrotitanium alloy comprises the following steps: s41, mixing 15-25% of titanium sponge, 48-54% of waste pure titanium and 25-33% of waste steel by mass with the titanium sponge, the waste pure titanium and the waste steel as raw materials; S42, adding ingredients into a furnace for smelting, adding a refining agent consisting of fluorite powder, potassium chloride and calcium oxide in the smelting process, and simultaneously refining and stirring in a bottom argon blowing mode, wherein the tapping temperature is controlled at 1050-1150 ℃; S43, rapidly solidifying after discharging, and obtaining the low-aluminum low-nitrogen ferrotitanium alloy.
5. The method for controlling the titanium element of the high-titanium welding wire steel, as claimed in claim 4, wherein the main component indexes of the low-aluminum low-nitrogen ferrotitanium alloy are Ti not less than 65%, al not more than 0.5% and N not more than 0.05%.
6. The method for controlling titanium element in high-titanium welding wire steel according to claim 5, wherein the continuous casting process adopts a calcia carbonless tundish covering agent.
7. The method for controlling the titanium element of the high-titanium welding wire steel, which is characterized in that the components of the calcium aluminate carbonless tundish covering agent comprise more than or equal to 50% of CaO, less than or equal to 8% of Al 2 0 3 ≥30%,SiO 2 , less than or equal to 8% of MgO and less than or equal to 0.5% of C by mass.
8. The method for controlling the titanium element of the high-titanium welding wire steel of claim 7, wherein in the continuous casting process, an integral submerged nozzle and a stopper rod are adopted for controlling flow so as to promote the whole protection of the continuous casting process.
9. The method for controlling the titanium element in the high-titanium welding wire steel according to claim 8, wherein the method comprises the following steps: The target range is 0.18-0.25%.
10. The method for controlling titanium element in high-titanium welding wire steel according to claim 9, wherein the steel grade is required to have nitrogen content less than or equal to 60ppm and aluminum content less than or equal to 0.02%.

Description

Method for controlling titanium element of high-titanium welding wire steel Technical Field The invention belongs to the technical field of high-titanium welding wire steel, and particularly relates to a method for controlling titanium element of high-titanium welding wire steel. Background The component design of the high-titanium welding wire steel surrounds the following components of ensuring welding performance, inhibiting precipitation of harmful phases and improving the cleanliness of molten steel: the key alloy element is titanium as core, and the content and the form are precisely controlled Titanium is a "characteristic element" of high titanium wire steels, and its content and morphology directly determine the weldability (e.g., porosity resistance, crack resistance) of the wire. The titanium content of the high-titanium welding wire steel is generally controlled to be 0.15% -0.35%, and the titanium needs to be adjusted according to the purpose of the welding wire, so that the main functions are to refine welding seam grains and reduce cold crack sensitivity. Therefore, the deoxidization in the steelmaking process is required, and the oxidation of titanium is strictly controlled. Titanium alloying generally adopts ferrotitanium alloy, but the content of Al element in ferrotitanium alloy is about 10 percent, the content of nitrogen is about 0.02 percent, when the content of titanium in titanium-containing steel is less than or equal to 0.1 percent, ferrotitanium alloy (30 ferroiron alloy, the main component Ti is more than or equal to 25 percent, al is less than or equal to 10 percent, 70 ferrotitanium Ti is more than or equal to 65 percent, al is less than or equal to 3.0 percent) has limited effect on increasing Al and N of steel, but the titanium content in high-titanium welding wire steel is high, and after the titanium component is regulated by ferrotitanium alloy, the Al and N of the molten steel are more, so that molten steel flocculation flow, component grid discharge and the like in the continuous casting process are realized, so that the accurate control of the titanium in the high-titanium welding wire steel is an industry technical pain point. (II) harmful elements (C, N, S, P) to avoid defects and performance degradation by ultra-low content control The high-titanium welding wire steel has extremely low tolerance to harmful elements, and needs to be controlled through the whole process of smelting and refining, and the core aims at reducing the reaction with titanium and reducing the weld defect risk. Generally, C is less than or equal to 0.10%, N is less than or equal to 0.007% (70 ppm), and S is less than or equal to 0.015%. Wherein, free N can form coarse TiN inclusion with Ti to cause slag inclusion of the welding seam, and excessive N can increase cold crack sensitivity of the welding seam. S and Ti form a low-melting-point compound, and are easy to enrich in a crystal boundary during welding, so that hot cracks are caused, and the low-temperature toughness and corrosion resistance of a welding line are reduced. P tends to gather at the weld grain boundary, resulting in cold embrittlement and increased weld crack sensitivity. (III) inclusion controlling element (Si, mn, al) auxiliary deoxidizing+stabilizing property Si, mn and Al are auxiliary elements of high-titanium welding wire steel, and have the main effects of deoxidizing, adjusting molten steel fluidity, avoiding interaction with titanium, and controlling the content of the Si, mn and Al. Aluminum final deoxidation and titanium morphology control, and the ultra-low content acid-soluble aluminum (effective aluminum) content needs to be strictly controlled. The aluminum is 0.005% -0.010% (50-100 ppm), the core function is to serve as a final deoxidizing element, the oxygen activity (Al+O- & gtAl 2O3) of molten steel is further reduced, ti is prevented from being oxidized into TiO 2, coarse Al-Ti-O composite inclusions (such as Al 2TiO5) are avoided from being formed with Ti if Al is over-high, weld seam pores or slag inclusions are caused, and if Al is over-low, the oxygen content of molten steel is over-high, so that titanium is easy to oxidize and lose efficacy. Disclosure of Invention The invention aims to overcome the defects in the prior art and provides a method for controlling the steel titanium element of a high-titanium welding wire. In order to achieve the purpose of the invention, the invention is implemented by adopting the following technical scheme. A method for controlling titanium element of high-titanium welding wire steel comprises the following steps of converter or electric furnace smelting, LF refining and continuous casting in sequence in the steelmaking production process according to target components of the high-titanium welding wire steel, wherein: When tapping in the converter or electric furnace smelting process, adding ferrosilicon alloy with equal silicon mass according to the mass of 90% of ta