A method for producing a black coil of copper-containing antibacterial martensitic stainless steel by a furnace roll mill

Abstract

The present application relates to the technical field of steel rolling production, in particular to a method for producing copper-containing antibacterial martensitic stainless steel black coil by a furnace rolling mill, which solves the problem that steel coil edge cracking and peeling defects easily occur in the rolling process of the copper-containing antibacterial martensitic stainless steel. The method mainly comprises the processes of slab preheating, heating, descaling, rough rolling, finish rolling, coiling and annealing, etc. By setting the heating temperature, the descaling water pressure and speed, the rough rolling and finish rolling pass compression ratio and controlling the annealing temperature, the high-quality hot-rolled black coil is finally rolled out, the defects such as steel coil edge cracking and surface peeling occurring in the process of preparing the copper-containing antibacterial martensitic stainless steel are effectively eliminated, and the plate width and the thick range of large coil plate of the copper-containing antibacterial martensitic stainless steel rolling production are further improved, so that the overall production efficiency and quality of the copper-containing antibacterial martensitic stainless steel are greatly improved.

Description

Technical Field

[0001] This invention relates to the field of steel rolling production technology, specifically to a method for producing copper-containing antibacterial martensitic stainless steel black coils using a hot-roll mill. Background Technology

[0002] Martensitic stainless steel is a type of stainless steel whose properties are adjusted through heat treatment. After heat treatment, it has good rust resistance and hardness, and is widely used in the kitchen knife industry. Currently, kitchen knife steel largely uses medium- and high-carbon martensitic stainless steels such as 30Cr13 and 40Cr13. However, with the increasing emphasis on health in recent years, antibacterial materials have begun to develop, and some martensitic antibacterial material grades have emerged both domestically and internationally, and are being applied in the kitchen knife industry, increasing their antibacterial properties and playing a positive role in people's health. Although copper-containing martensitic stainless steel has been used in kitchen knives, large-scale industrial mass production is limited, and most production is carried out in small batches using ingot forging methods. Furthermore, hot working is only one step in the process, lacking specific parameter control requirements for the thermal process of copper-containing martensitic stainless steel. Ultimately, this results in poor process control during production, making it prone to defects such as peeling and edge cracking. Summary of the Invention

[0003] This invention provides a method for producing copper-containing antibacterial martensitic stainless steel black coils using a hot-roll mill, in order to solve the problems of edge cracking and peeling that easily occur during the rolling process of copper-containing antibacterial martensitic stainless steel, as mentioned above.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A method for producing copper-containing antibacterial martensitic stainless steel black coils using a hot-rolling mill includes the following steps:

[0006] Step 1, Slab heating: The 220mm thick slab cut from continuous casting is sent to the preheating furnace for preheating. The furnace exit temperature is 500℃-600℃. After preheating, the slab is sent to the heating furnace for heating and holding. The heating temperature is 1000℃-1050℃, and the heating rate is 3℃ / min.

[0007] Step 2, Surface descaling: After the slab exits the heating furnace, it enters the descaling machine and is descaled by high-pressure water. The water pressure is ≥250 bar and the descaling rate is 2 m / s.

[0008] Step 3, rough rolling: The descaled slab is rolled in intermediate passes, with reduction rates of 40%-45%, 30%-35%, 30%-35%, 20%-25%, and 20%-25% respectively, and the rolling speed is 5m / s.

[0009] Step 4, Finish rolling: The intermediate billet after rough rolling is finished rolled in 7 passes with reduction rates of 20%-40%, 15%-30%, 15%-30%, 15%-30%, 15%-30%, 15%-30%, and 10%-20% respectively, and the rolling speed is 9m / s.

[0010] Step 5, Coiling: After finishing rolling, the steel strip is quickly coiled at a speed of 2m / s - 7m / s and a temperature of 600℃ - 700℃.

[0011] Step 6, Annealing: After the coils are rolled off the production line and cooled to 300℃-400℃, the hot coils are directly put into a hydrogen bell-type furnace for annealing. The annealing temperature is 820℃-850℃, and the annealing holding time is 10h-15h. After that, they are slowly cooled to 200℃-250℃ and then taken out of the furnace. After the black coils are taken out of the furnace, they are cooled to room temperature and then packaged.

[0012] Furthermore, in step 1, the slab is held in the preheating furnace for 150-200 minutes and in the heating furnace for 150-180 minutes.

[0013] Furthermore, the thickness of the intermediate billet after rough rolling in step 3 is 25mm-40mm.

[0014] Furthermore, in step 6, the width of the black rolls after baking is 1000 mm - 1530 mm, and the thickness is 3 mm - 12 mm.

[0015] The present invention has the following beneficial effects:

[0016] This invention provides a method for producing copper-containing antibacterial martensitic stainless steel black coils using a hot-rolling mill. The method mainly includes processes such as slab preheating, heating, descaling, rough rolling, finish rolling, coiling, and annealing. By setting the heating temperature, descaling water pressure and rate, the compression ratio of rough rolling and finish rolling passes, and controlling the annealing temperature, high-quality hot-rolled black coils are finally produced. This effectively eliminates defects such as edge cracking and surface peeling that occur during the preparation of copper-containing antibacterial martensitic stainless steel. Furthermore, it increases the width of the plates and the thickness range of large coils produced from copper-containing antibacterial martensitic stainless steel, thereby greatly improving the overall production efficiency and quality of copper-containing antibacterial martensitic stainless steel. It solves the problem of edge cracking and peeling defects that are easily encountered during the current rolling process of copper-containing antibacterial martensitic stainless steel. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the appearance of the rolled edge of the copper-containing antibacterial martensitic stainless steel in this invention.

[0018] Figure 2 This is a schematic diagram of the surface appearance of the copper-containing antibacterial martensitic stainless steel coil after pickling during rolling in this invention. Detailed Implementation

[0019] The present invention will be further described below with reference to specific embodiments.

[0020] Example 1

[0021] A method for producing copper-containing antibacterial martensitic stainless steel black coils using a hot-rolling mill includes the following steps:

[0022] Step 1, Slab heating: The 220mm thick slabs cut from continuous casting are sent to the preheating furnace for preheating. The furnace temperature is 500℃ and the holding time is 150min. After preheating, the slabs are sent to the heating furnace for heating and then held at 1000℃. The heating rate is 3℃ / min and the holding time is 150min.

[0023] Step 2, Surface descaling: After exiting the furnace, the slab enters the descaling machine and is descaled once using high-pressure water at a pressure of 250 bar and a descaling rate of 2 m / s.

[0024] Step 3, rough rolling: The descaled slab is rolled in intermediate rolling with 5 passes, with reduction rates of 40%, 30%, 30%, 20%, and 20% respectively, at a rolling speed of 5 m / s, until the intermediate slab thickness is 25 mm.

[0025] Step 4, Finish rolling: The intermediate billet, which has been rough rolled to a thicker thickness, is then finished rolled in 7 passes with reduction rates of 20%, 15%, 15%, 15%, 15%, 15%, 10%, and 10% respectively. The rolling speed is 9 m / s, and the final product is rolled to a thickness of 3 mm.

[0026] Step 5, Coiling: After rolling, the steel strip is quickly coiled at a speed of 2 m / s and a temperature of 600℃.

[0027] Step 6, Annealing: After the hot rolls are cooled to 300°C after coming off the production line, they are directly loaded into a bell-type furnace for annealing at 820°C. After holding the annealing temperature for 15 hours, they are slowly cooled to 200°C before being taken out of the furnace. After the hot rolls are taken out of the furnace, they are cooled to room temperature and then packaged.

[0028] Example 2

[0029] A method for producing copper-containing antibacterial martensitic stainless steel black coils using a hot-rolling mill includes the following steps:

[0030] Step 1, Slab heating: The 220mm thick slab cut from continuous casting is sent to the preheating furnace for preheating. The furnace temperature is 550℃ and the holding time is 180min. After preheating, the slab is sent to the heating furnace for heating and then held at 1030℃. The heating rate is 3℃ / min and the holding time is 170min.

[0031] Step 2, Surface descaling: After exiting the furnace, the slab enters the descaling machine and is descaled once using high-pressure water at a pressure of 260 bar and a descaling rate of 2 m / s.

[0032] Step 3, rough rolling: The descaled slab is rolled in intermediate passes of 5 passes with reduction rates of 41%, 32%, 32%, 22%, and 22% respectively. The rolling speed is 5 m / s and the thickness of the intermediate slab is 35 mm.

[0033] Step 4, Finish rolling: The intermediate billet, which has been rough rolled to a thicker thickness, is then finished rolled in 7 passes with reduction rates of 29%, 24%, 21%, 21%, 20%, 20%, and 15% respectively. The rolling speed is 9 m / s, and the final product is rolled to a thickness of 6 mm.

[0034] Step 5, Coiling: After rolling, the steel strip is quickly coiled at a speed of 5 m / s and a temperature of 650℃.

[0035] Step 6, Annealing: After the hot rolls are cooled to 350°C after coming off the production line, they are directly loaded into a bell-type furnace for annealing at 830°C. After holding the annealing temperature for 15 hours, they are slowly cooled to 230°C before being taken out of the furnace. After the hot rolls are taken out of the furnace, they are cooled to room temperature and then packaged.

[0036] Example 3

[0037] A method for producing copper-containing antibacterial martensitic stainless steel black coils using a hot-rolling mill includes the following steps:

[0038] Step 1, Slab heating: The 220mm thick slabs cut from continuous casting are sent to the preheating furnace for preheating. The furnace temperature is 600℃ and the holding time is 200min. After preheating, the slabs are sent to the heating furnace for heating and then held at 1050℃. The heating rate is 3℃ / min and the holding time is 180min.

[0039] Step 2, Surface descaling: After exiting the furnace, the slab enters the descaling machine and is descaled once using high-pressure water at a pressure of 280 bar and a descaling rate of 2 m / s.

[0040] Step 3, rough rolling: The descaled slab is rolled in intermediate passes of 5 passes with reduction rates of 45%, 35%, 35%, 25%, and 25% respectively. The rolling speed is 5 m / s and the thickness of the intermediate slab is 40 mm.

[0041] Step 4, Finish rolling: The intermediate billet, which has been rough rolled to a thicker thickness, is then finished rolled in 7 passes with reduction rates of 40%, 30%, 30%, 30%, 30%, 30%, and 20% respectively. The rolling speed is 9 m / s, and the final product is rolled to a thickness of 12 mm.

[0042] Step 5, Coiling: After rolling, the steel strip is quickly coiled at a speed of 7 m / s and a temperature of 700℃.

[0043] Step 6, Annealing: After the hot rolls are cooled to 400°C after coming off the production line, they are directly loaded into a bell-type furnace for annealing at 850°C. After holding the annealing temperature for 15 hours, they are slowly cooled to 250°C before being taken out of the furnace. After the hot rolls are taken out of the furnace, they are cooled to room temperature and then packaged.

[0044] After producing copper-containing antibacterial martensitic stainless steel black coils using the hot rolling mills in Examples 1-3, the following results were obtained: Figure 1-2 The images shown depict the edge appearance of the copper-containing antibacterial martensitic stainless steel coil and the surface appearance after pickling. Analysis of the images reveals that by optimizing the parameters of the rolling furnace heating temperature, descaling water pressure and rate, roughing and finishing rolling pass compression ratio, and annealing temperature, copper-containing antibacterial martensitic stainless steel with eliminated edge cracks and surface peeling defects was finally produced. Furthermore, the width of the plates and the thickness of the large coils produced by rolling copper-containing antibacterial martensitic stainless steel were increased, greatly improving the overall production efficiency and quality of copper-containing antibacterial martensitic stainless steel.

Claims

1. A method for producing copper-containing antibacterial martensitic stainless steel black coils using a hot rolling mill, characterized in that, Includes the following steps: Step 1, Slab heating: The 220mm thick slab cut from continuous casting is sent to the preheating furnace for preheating. The furnace exit temperature is 500℃-600℃. After preheating, the slab is sent to the heating furnace for heating and holding. The heating temperature is 1000℃-1050℃ and the heating rate is 3℃ / min. Step 2, Surface descaling: After the slab exits the heating furnace, it enters the descaling machine and is descaled by high-pressure water. The water pressure is ≥250 bar and the descaling rate is 2 m / s. Step 3, rough rolling: The descaled slab is rolled in intermediate passes, with reduction rates of 40%-45%, 30%-35%, 30%-35%, 20%-25%, and 20%-25% respectively. The rolling speed is 5m / s, and the thickness of the intermediate slab after rough rolling is 25mm-40mm. Step 4, Finish rolling: The intermediate billet after rough rolling is finished rolled in 7 passes with reduction rates of 20%-40%, 15%-30%, 15%-30%, 15%-30%, 15%-30%, 15%-30% and 10%-20% respectively, and the rolling speed is 9m / s. Step 5, Coiling: After finishing rolling, the steel strip is quickly coiled at a speed of 2m / s - 7m / s and a temperature of 600℃ - 700℃. Step 6, Annealing: After the coils are rolled off the production line and cooled to 300℃-400℃, the hot coils are directly put into a hydrogen bell-type furnace for annealing. The annealing temperature is 820℃-850℃, and the annealing holding time is 10h-15h. After that, they are slowly cooled to 200℃-250℃ and then taken out of the furnace. The width of the black coils after taking out of the furnace is 1000 mm-1530 mm, and the thickness is 3mm-12mm. After cooling to room temperature, they can be packaged.

2. The method for producing copper-containing antibacterial martensitic stainless steel black coils using a hot rolling mill according to claim 1, characterized in that: In step 1, the slab is held in the preheating furnace for 150-200 minutes and in the heating furnace for 150-180 minutes.

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