CN-121975997-A - Smelting method of 25MnB-1 accurate titanium control under duplex technology

Abstract

The invention discloses a smelting method for precisely controlling titanium by 25MnB-1 in a duplex process, and belongs to the technical field of smelting. The method comprises the steps of firstly raising the temperature to be lower than the conventional outlet temperature in the later treatment stage of an LF refining furnace, adjusting bottom blowing to be in a strong and soft blowing state, adding ferrotitanium alloy to an argon port to reach the middle limit of the internal control requirement of components, then adjusting the bottom blowing to be in a weak and soft blowing state, closing the bottom blowing to enable the alloy to be fully and uniformly melted, carrying out deep vacuum treatment on an RH vacuum furnace for 5-7min after molten steel arrives at the station, carrying out calcium treatment after the RH vacuum furnace is broken, and finishing smelting of 25MnB-1 steel types in a duplex process. The method reduces the power consumption per ton of steel of the LF refining furnace, prolongs the service life of refractory materials of the RH vacuum furnace and reduces the alloy cost, and the improvement comprises the improvement of the purity of molten steel.

Inventors

• Si Junliang
• WANG FANGDONG
• YU MAOYUAN
• MA MENGHAN
• SUN QING
• LI LIANG
• ZHANG ZHENGHUA
• CHEN CANPING
• XUE RONGJUN
• LI HONGBIN
• GU YUFENG
• Sun tianyi

Assignees

• 临沂钢铁投资集团特钢有限公司

Dates

Publication Date

20260505

Application Date

20260225

Claims (6)

1. 1. The smelting method of the 25MnB-1 accurate titanium control under the duplex technology is characterized by comprising the following steps: (1) In the later treatment stage of the LF refining furnace, the temperature is increased to the outlet temperature, bottom blowing is adjusted to a strong and soft blowing state, power transmission is stopped, and ferrotitanium is added to an argon port until the middle limit of the component internal control requirement; (2) Adjusting the bottom blowing to a weak soft blowing state, starting to a bag hanging position until the crown block is started to hang, and closing the bottom blowing to enable the alloy to be fully and uniformly melted; (3) After the molten steel arrives at the station, the RH vacuum furnace starts vacuum treatment, the RH vacuum furnace carries out deep vacuum treatment for 5-7min, and calcium treatment is carried out after the RH vacuum furnace breaks the air, so that the 25MnB-1 steel grade smelting under the duplex technology is completed.
2. 2. The method for smelting 25MnB-1 accurate titanium control under the duplex technology according to claim 1, wherein in the step (1), the outlet temperature is 1615+/-5 ℃, and the air flow rate in the strong soft blowing state is 115+/-15 NL/min.
3. 3. The smelting method of the 25MnB-1 accurate titanium control under the duplex technology according to claim 1, wherein in the step (1), when ferrotitanium is added, the ferrotitanium directly enters molten steel under the condition of not contacting a slag layer.
4. 4. The method for smelting 25MnB-1 accurate titanium control under the duplex technology according to claim 1, wherein in the step (2), the gas used in the weak soft blowing state is argon, and the flow is 90+/-10 NL/min.
5. 5. The method for smelting 25MnB-1 accurate titanium control under the duplex process according to claim 1, wherein in the step (3), the circulation flow amount is 800L/min in the first 3 minutes and is regulated to 1300+/-100L/min in 3-7 minutes during vacuum treatment.
6. 6. The use of the smelting method according to any one of claims 1 to 5 for reducing consumption and improving quality, wherein the consumption reduction comprises reducing the power consumption per ton of steel in an LF refining furnace, prolonging the service life of refractory materials in an RH vacuum furnace and reducing the cost of alloy, and the improvement comprises improving the purity of molten steel.

Description

Smelting method of 25MnB-1 accurate titanium control under duplex technology Technical Field The invention relates to the technical field of smelting, in particular to a smelting method for precisely controlling titanium in 25MnB-1 by a duplex process. Background The 25MnB series belongs to high-quality alloy structural steel, and is classified as boron-containing quenched and tempered steel for cold heading and cold extrusion by Chinese standard GB/T3077-2015 alloy structural steel. The core advantage of the method is that the hardenability is obviously improved by the trace boron element (0.0008% -0.0035%), the ferrite phase transformation is inhibited, and the strength and toughness balance is optimized. The material has high plasticity, good weldability and cold formability, and is suitable for manufacturing high-strength parts. When a duplex process (converter-LF refining furnace-RH vacuum furnace-continuous casting) is used for smelting 25MnB-1 steel with the trade name of 25MnB-1 in the 25MnB series, titanium wires are added when the RH vacuum furnace is used for smelting 25MnB-1 steel, and the component titanium is required to be subjected to calcium treatment in the RH vacuum furnace. The prior art has the following defects that 1, excessive wires are added in a calcium treatment stage, the temperature of the whole wire feeding process is reduced to be more than 10 ℃, the temperature loss is larger, because an RH vacuum furnace in a duplex process is forbidden to blow oxygen and raise temperature, an LF refining furnace is forced to be raised to the temperature of the RH vacuum furnace, the power consumption of ton steel of the LF refining furnace is raised, 2, the continuous high temperature is particularly serious for scouring and eroding the refractory materials of the RH vacuum furnace, the service life of the refractory materials of the RH vacuum furnace is lower, 3, titanium wires are higher than ferrotitanium, and because the components of the bulk titanium wires are unstable, the cost of alloy is wasted due to the fact that the components of titanium are controlled according to an internal control upper limit, and 4, titanium oxide inclusions such as titanium dioxide are easy to be generated in the later smelting stage of the RH vacuum furnace, the molten steel is not floated enough time, the molten steel is polluted, and the purity of the molten steel is reduced. Therefore, a targeted smelting method needs to be developed to solve the above problems. Disclosure of Invention Aiming at the prior art, the invention aims to provide a smelting method for precisely controlling titanium of 25MnB-1 in a duplex process. In order to achieve the above purpose, the invention adopts the following technical scheme: The invention provides a smelting method of 25MnB-1 accurate titanium control under a duplex process, which comprises the following steps: (1) In the later treatment stage of the LF refining furnace, the temperature is increased to the outlet temperature, bottom blowing is adjusted to a strong and soft blowing state, power transmission is stopped, and ferrotitanium is added to an argon port until the middle limit of the component internal control requirement; (2) Adjusting the bottom blowing to a weak soft blowing state, starting to a bag hanging position until the crown block is started to hang, and closing the bottom blowing to enable the alloy to be fully and uniformly melted; (3) After the molten steel arrives at the station, the RH vacuum furnace starts vacuum treatment, the RH vacuum furnace carries out deep vacuum treatment for 5-7min, and calcium treatment is carried out after the RH vacuum furnace breaks the air, so that the 25MnB-1 steel grade smelting under the duplex technology is completed. Further, in the step (1), the outlet temperature is 1615+ -5 ℃, and the air flow rate in the strong and soft blowing state is 115+ -15 NL/min. Further, in the step (1), when ferrotitanium is added, the ferrotitanium directly enters molten steel without contacting a slag layer. In the step (2), argon is used in the weak soft blowing state, and the flow is 90+/-10 NL/min. Further, in the step (3), during vacuum treatment, the circulation flow rate is 800L/min in the first 3 minutes, and the circulation flow rate is adjusted to 1300+/-100L/min in 3-7 minutes. The invention provides an application of the smelting method in consumption reduction and quality improvement, wherein the consumption reduction comprises the steps of reducing the power consumption of ton steel of an LF refining furnace, prolonging the service life of refractory materials of an RH vacuum furnace and reducing the alloy cost, and the quality improvement comprises the step of improving the purity of molten steel. The invention has the beneficial effects that: The invention discloses a smelting method of 25MnB-1 accurate titanium control under a duplex process, which comprises the steps of firstly raising the temperature to an