S45C carbon plate shape control method

Abstract

The invention discloses a method for controlling the shape of an S45C carbon plate, and belongs to the field of metallurgy, in particular to a method for adjusting the matching of a straightening roller gap and a straightening temperature during straightening, which specifically comprises the following steps of: adjusting the inlet roller gap of a straightening machine to be h-(4-5) mm, and adjusting the outlet roller gap of the straightening machine to be h-(1.5-2.5) mm, wherein h is the actual thickness of the carbon plate; the final rolling temperature of the carbon plate is 850 DEG C, steel placing is conducted for 10-15 s before straightening, then the steel is conveyed to a straightening machine, and the straightening temperature is controlled to be 650-700 DEG C; the method is simple and easy to implement, the probability of secondary deformation of the steel plate is effectively reduced, and the qualified rate of steel plate production is increased.

Description

Technical Field

[0001] The invention relates to a plate shape control method, in particular to a S45C carbon plate shape control method, and belongs to the field of metallurgy. Background Art

[0002] S45C steel is a fully static steel made by electric furnace, open hearth furnace or pure oxygen converter steelmaking method. The steel has uniform metallographic structure and no structural defects.

[0003] S45C carbon steel is widely used in machinery manufacturing. This steel has good mechanical properties and a carbon content of more than 0.4%. During the rolling process, it is easy to undergo secondary deformation on the cooling bed after online straightening, requiring an additional offline straightening process, which increases the overall production cost.

[0004] Patent CN102500658B discloses a hot straightening method for achieving plate shape control of extra-thick plates. It discloses controlling the plate shape during hot straightening by controlling the straightening roll gap, changing the original design of staggered distribution of working rolls, and adopting parallel distribution of upper and lower working rolls. This effectively solves the problem that steel plates with a thickness greater than 100 mm cannot be straightened after rolling. The shape quality of the steel plates is guaranteed, meeting the market demand for extra-thick steel plates. At the same time, it can also protect the straightening equipment. It is mainly for steel plates with a thickness greater than 100 mm, and is not described for those below 100 mm. In addition, the carbon content of the steel is also different and is not applicable.

[0005] Patent CN105834226B discloses a method for controlling the shape of a Q345E steel plate. By controlling the straightening temperature and the final rolling temperature of the steel plate, the temperature and internal thermal stress of the steel plate are evenly distributed. When the thermal stress does not exceed the yield strength of the material, plastic deformation will not occur. From the appearance, the steel plate will not have shape defects such as wave shape, warping, transverse bending, bulging, etc. However, it is limited to temperature adjustment, and the degree of improvement is limited. There is still room for improvement. In addition, the material of the steel is different, and the process is also different.

[0006] Therefore, developing a method for controlling the shape of an S45C carbon plate that can overcome the above defects has become a technical problem that needs to be solved urgently by those skilled in the art. Summary of the invention

[0007] The technical problem to be solved by the present invention is to propose a method for controlling the shape of S45C carbon plate in view of the shortcomings of the above-mentioned prior art. The method is simple and easy to implement, effectively reduces the probability of secondary deformation of the steel plate, and improves the qualified rate of steel plate production.

[0008] The technical solution of the present invention to solve the above technical problems is: A method for controlling the shape of an S45C carbon plate, wherein the roller gap and the straightening temperature are adjusted during straightening, specifically: Adjust the entrance roller gap of the straightening machine to h- (4~5) mm, Adjust the exit roller gap of the straightening machine to h-(1.5~2.5)mm, Where: h is the actual thickness of the carbon plate; The final rolling temperature of carbon plate is 850℃. The steel is swung before straightening and then transported to the straightening machine. The straightening temperature is controlled at 650-700℃.

[0009] The technical solution further defined in the present invention is: In the above-mentioned method for controlling the shape of S45C carbon plate, the straightening machine entrance roll gap is h-4mm, and the exit roll gap is h-1.5mm, where h is the actual thickness of the steel plate.

[0010] In the aforementioned method for controlling the shape of the S45C carbon plate, the straightening temperature is controlled to be 700°C.

[0011] In the above-mentioned method for controlling the shape of the S45C carbon plate, the swinging time is controlled to be 10 to 15 seconds when swinging the steel before correction.

[0012] In the aforementioned method for controlling the shape of the S45C carbon plate, the thickness of the S45C carbon plate is 8-25 mm.

[0013] The beneficial effects of the present invention are: The present invention is aimed at the straightening process of carbon plates, mainly such S45C steel plates with high carbon content and thickness below 100 mm, which have low hardness under high temperature conditions. The present invention coordinates the roller gap with the straightening temperature to reduce the buckling rate in the production process of S45C carbon steel. Through this method, the first-time qualified rate of S45C carbon plates can be effectively increased by 2%. 30,000 tons of steel plates can be produced annually, the steel plate straightening and flattening cost is 50 yuan / ton, and the benefit is 30,000*2%*50 = 30,000 yuan. DETAILED DESCRIPTION Example 1

[0014] This embodiment provides a method for controlling the plate shape of S45C carbon plate. Taking the production of 12.5mm JIS-S45C as an example, the roll gap and the straightening temperature are adjusted during straightening. Specifically, the inlet roll gap of the straightening machine is adjusted to 7.55mm, the outlet roll gap is adjusted to 11.05mm, the final rolling temperature of the carbon plate is 850°C, the steel is swung for 12s before straightening, and then it is transported to the straightening machine, and the straightening temperature is controlled to 700°C.

[0015] In order to control the change of the plate shape of the steel plate on the cooling bed, the present invention adjusts the online straightening of the steel plate; in order to ensure that the plate shape of the steel plate is normal after online straightening, the straightening parameters are adjusted and solidified; the straightening state temperature of the steel plate is optimized, and the rolling process temperature of the steel plate and the temperature control before straightening are adjusted. Through the precise control of the previous process, the stable and qualified plate shape of the steel plate after the rolling, straightening and cooling processes is further ensured. By optimizing these aspects, the S45C carbon plate rolling plate shape control method is realized.

[0016] By comparing the roll gap and straightening force of straighteners of different specifications, the straightening process and straightening temperature of straighteners under different specifications are fixed to ensure that the steel plate will not undergo secondary deformation after straightening by this process; according to the actual production situation, the final rolling temperature of S45C carbon plate is controlled below 850℃, and the straightening temperature is reduced to below 700℃ by transporting it to the straightener at a low speed or taking measures to swing the steel in front of the straightener, which can effectively reduce the incidence of secondary deformation of the steel plate after straightening.

[0017] Through this method, the first-time qualified rate of S45C carbon plate production can be effectively increased by 2%. 30,000 tons of steel plates can be produced annually, and the steel plate straightening and flattening cost is 50 yuan / ton, generating benefits of 30,000*2%*50 = 30,000 yuan.

[0018] In addition to the above embodiments, the present invention may also have other implementation modes. Any technical solution formed by equivalent replacement or equivalent transformation falls within the protection scope required by the present invention.

Claims

1. A method for controlling the shape of an S45C carbon plate, characterized in that: When straightening, adjust the roller gap and straightening temperature, specifically: Adjust the entrance roller gap of the straightening machine to h- (4~5) mm, Adjust the exit roller gap of the straightening machine to h-(1.5~2.5)mm, Where: h is the actual thickness of the carbon plate; The final rolling temperature of carbon plate is 850℃. The steel is swung before straightening and then transported to the straightening machine. The straightening temperature is controlled at 650-700℃.

2. The method for controlling the shape of an S45C carbon plate according to claim 1, characterized in that: The inlet roll gap of the straightening machine is h-4mm, and the outlet roll gap is h-1.5mm, where h is the actual thickness of the carbon plate.

3. The method for controlling the shape of an S45C carbon plate according to claim 1, characterized in that: The controlled straightening temperature is 700°C.

4. The method for controlling the shape of an S45C carbon plate according to claim 1, characterized in that: When swinging steel before correction, the swinging time is controlled to be 10~15s.

5. The method for controlling the shape of an S45C carbon plate according to claim 1, characterized in that: The S45C carbon plate has a thickness of 8-25 mm.