CN-122007356-A - Method for reducing internal defects of die steel, application of method and die steel

Abstract

The invention discloses a method for reducing internal defects of die steel, application of the method and the die steel, and relates to the technical field of steel production. The method comprises the steps of delivering refined molten steel to a continuous casting machine for continuous casting into a casting blank, wherein the reduction between two adjacent fan-shaped sections of the continuous casting machine is 0.01-1 mm. The rolling reduction between two adjacent fan-shaped sections of the continuous casting machine is controlled to be 0.01-1 mm, continuous transmission of pressure between the sections can be realized in the continuous casting blank drawing process, and the stress uniformity of the casting blank in the transition area of the fan-shaped sections is effectively improved, so that the risk of bulging of the casting blank is reduced, the internal stress concentration of the casting blank is reduced, the defects of cracks or shrinkage cavities in the casting blank are reduced, and the stability and consistency of the overall internal quality of the casting blank are improved.

Inventors

• LIN TING
• LIU MIN
• Bian Huiyu
• MA PENG
• LI QIANG
• SU XING
• HUANG KAI
• ZHONG HUA
• LIAO XIAOWEN
• ZOU JINZHONG
• WANG KUNMING
• ZHANG JIALIANG
• WANG XUELIN
• WANG WEI
• LI SHIHENG
• GONG JIAJUN
• Ye Zhenyao
• XIA PENG
• GUO MINGQING
• Mao Weigen
• WANG JINLIN
• ZHANG YANAN
• WEN WEIPING
• GUO WENBO
• YUAN CHUANQUAN
• XIE GUIQIANG
• LI JIAQI

Assignees

• 新余钢铁股份有限公司

Dates

Publication Date

20260512

Application Date

20260305

Claims (8)

1. 1. A method for reducing internal defects of die steel is characterized by comprising the steps of delivering refined molten steel to a continuous casting machine for continuous casting into a casting blank, wherein the reduction between two adjacent fan-shaped sections of the continuous casting machine is 0.01-1 mm.
2. 2. The method according to claim 1, wherein the sector area of the continuous casting machine corresponding to the solidification end of the cast slab is a main reduction section, the reduction between two adjacent sectors in the main reduction section is 0.03-1 mm, and the reduction between two adjacent sectors in the non-main reduction section is 0.01-0.05 mm.
3. 3. The method of claim 2, wherein the reduction of each segment in the non-main reduction is 0.3-0.7 mm and the reduction of each segment in the main reduction is 1-5 mm.
4. 4. The method according to claim 2, wherein 16 fan-shaped sections are sequentially arranged along the moving direction of the casting blank in the continuous casting machine, the 9 th section to the 11 th section are the main reduction sections, the reduction of the 9 th section is 1-3 mm, the reduction of the 10 th section is 3-5 mm, and the reduction of the 11 th section is 1-3 mm.
5. 5. The method of claim 1, wherein each segment has a frame and the master power system of the caster controls the amount of reduction of each frame, and wherein the method of reducing internal defects in the mold steel further comprises reducing the opening pressure of the frame and/or increasing the total pressure of the master power system of the caster.
6. 6. The method of claim 1, further comprising flaw detecting the cast slab with a flaw detector having a flaw detection depth of 0-300 mm.
7. 7. A die steel, characterized in that the preparation method comprises the method according to any one of claims 1 to 6.
8. 8. Use of the method according to any one of claims 1 to 6 for producing a die steel.

Description

Method for reducing internal defects of die steel, application of method and die steel Technical Field The invention relates to the technical field of steel production, in particular to a method for reducing internal defects of die steel, application of the method and the die steel. Background As an important material in industrial production, the plastic mold steel is widely applied to the fields of plastic products, medical appliances, small household appliance manufacturing and the like. The current market demands for brands such as P20/L, 1.2311/H and 738/H are large. However, in the production process of the plastic mold steel, holes and cracks are easy to exist in the plastic mold steel, so that the flaw detection of the steel plate is not qualified. In order to reduce defects such as holes, cracks, etc. in the die steel, it is generally necessary to increase the compression ratio to effectively compact the defects during rolling. However, an excessively high compression ratio means a larger reduction, which not only limits the development of the product toward the thick plate, but also reduces the production efficiency and increases the difficulty of process control. The conventional compression ratio of the existing die steel is generally controlled to be 3-5 under the restriction of the capacity of a rolling mill, and the process stability is good in the range. Under the limit of the compression ratio, the thickness of the casting section of the continuous casting blank is required to reach more than 400mm for producing the die steel with the thickness of more than 140 mm. As the section increases, internal defects of the cast slab are more difficult to control, and thus the continuous casting machine is generally required to be equipped with an electromagnetic stirring function. However, it is difficult to realize a continuous casting machine unit with electromagnetic stirring specially configured for a single product category in actual production. Therefore, how to effectively reduce internal defects in the continuous casting process of thick section die steel under the condition of no electromagnetic stirring becomes a technical problem to be solved in the field. In view of this, the present invention has been made. Disclosure of Invention The invention aims to provide a method for reducing internal defects of die steel, application of the method and the die steel. The invention is realized in the following way: in a first aspect, the invention provides a method for reducing internal defects of die steel, comprising the steps of delivering refined molten steel to a continuous casting machine for continuous casting into a casting blank, wherein the reduction between two adjacent fan-shaped sections of the continuous casting machine is 0.01-1 mm. In an alternative embodiment, the sector section area of the continuous casting machine corresponding to the solidification end of the casting blank is a main reduction section, the reduction between two adjacent sectors in the main reduction section is 0.03-1 mm, and the reduction between two adjacent sectors in the non-main reduction section is 0.01-0.05 mm. In an alternative embodiment, the rolling reduction of each sector in the non-main rolling section is 0.3-0.7 mm, and the rolling reduction of each sector in the main rolling section is 1-5 mm. In an alternative embodiment, 16 fan-shaped sections are sequentially arranged along the moving direction of the casting blank by the continuous casting machine, the 9 th section to the 11 th section are main reduction sections, the reduction of the 9 th section is 1-3 mm, the reduction of the 10 th section is 3-5 mm, and the reduction of the 11 th section is 1-3 mm. In an alternative embodiment, each segment has a frame, the master power system of the caster controls the amount of reduction of each frame, and the method of reducing internal defects in the mold steel further includes reducing the opening pressure of the frame and/or increasing the total pressure of the master power system of the caster. In an optional embodiment, the method further comprises the step of detecting the flaw of the casting blank by using a flaw detector, wherein the flaw detection depth of the flaw detector is 0-300 mm. In a second aspect, the present invention provides a die steel, the method of making comprising the method of any of the preceding embodiments. In a third aspect, the present invention provides the use of a method according to any of the preceding embodiments for the preparation of a die steel. The invention has the following beneficial effects: The invention provides a method for reducing internal defects of die steel, application of the method and the die steel, wherein the continuous transmission of pressure between segments can be realized in the continuous casting blank drawing process by controlling the reduction of two adjacent fan-shaped segments of a continuous casting machine to be 0.01-1 mm, so that th