Method for eliminating stamping galling of hot-rolled automobile structural steel
By optimizing the hot rolling, laminar flow cooling, and coiling processes to control the thickness of the iron oxide scale, the problem of roughening during hot rolling sheet stamping was solved, improving product quality and production efficiency.
Patent Information
- Application Number
- CN202511148398.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-17
- Publication Date
- 2025-11-14
AI Technical Summary
During the hot-rolled sheet stamping process, roughening frequently occurs, affecting product quality and production efficiency, and existing research has been unable to completely avoid it.
By optimizing the hot rolling, laminar cooling, and coiling processes, the thickness of the iron oxide scale on the steel plate surface is controlled to be 21-24μm, forming a continuous isolation layer to reduce friction and eliminate roughening.
It improves the surface quality and fatigue resistance of automotive parts, reduces scrap rates, and enhances production efficiency and corporate competitiveness.
Smart Images
Figure CN120940377A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of steel strip production technology, specifically relating to a method for eliminating stamping roughening of hot-rolled automotive structural steel. Background Technology
[0002] In the metal processing industry, hot-rolled sheet stamping is a widely used process, extensively employed in industries such as automobile manufacturing and machining, to produce various parts, such as automotive body structural components. However, during the hot-rolled sheet stamping process, roughening frequently occurs, severely impacting product quality and production efficiency.
[0003] From a product quality perspective, roughening creates noticeable scratches and uneven textures on the surface of stamped parts, significantly reducing surface quality. For products with stringent surface quality requirements, such as automotive exterior parts, these roughening defects not only affect aesthetics but can also hinder subsequent surface treatment processes like painting and electroplating, reducing coating adhesion and making the product more susceptible to corrosion and rust, thus shortening its lifespan. From a production efficiency perspective, roughening leads to accelerated mold wear, frequent mold repairs and replacements, increasing production costs and extending production cycles, impacting the company's production plans and delivery capabilities. In automotive production, mold roughening can cause frequent downtime on stamping production lines, reducing production efficiency and increasing costs.
[0004] Research on the problem of roughening has made some progress. Scholars have found that the surface roughness, hardness, and lubrication conditions of the die are all closely related to roughening. When the die surface roughness is too high, the hot-rolled sheet is prone to generating significant friction with the die surface during stamping, leading to localized adhesion and tearing of the material, resulting in roughening. Insufficient die hardness makes it prone to plastic deformation under stamping pressure, which also promotes roughening. Poor lubrication conditions, which fail to effectively reduce the coefficient of friction between the hot-rolled sheet and the die, also increase the risk of roughening.
[0005] While existing research provides some theoretical basis for solving the problem of roughening during hot-rolled sheet stamping, the complex and variable stamping conditions in actual production processes make it difficult to completely avoid roughening. Therefore, in-depth research on the roughening problem in hot-rolled sheet stamping and exploring more effective prevention and solutions are of significant practical importance. This will help improve product quality, increase production efficiency, and reduce production costs. Summary of the Invention
[0006] The purpose of this invention is to provide a method for eliminating the scratching of hot-rolled automotive structural steel during stamping.
[0007] To achieve the above objectives, the present invention adopts the following technical solution: A method for eliminating stamping roughening of hot-rolled automotive structural steel involves optimizing and controlling the hot rolling, laminar cooling, and coiling processes during steel plate production to form a 21-24mm iron oxide scale on the surface of the automotive structural steel.
[0008] Furthermore, in the hot rolling process, the heating temperature is 1180-1260℃; the finishing rolling inlet temperature is 1000-1050℃; and the final rolling temperature is 880-920℃.
[0009] Furthermore, the laminar flow cooling process employs front-end cooling with a cooling rate of 40-60℃ / s.
[0010] Furthermore, in the winding process, the winding temperature is 580-620℃.
[0011] The inventive principle of the technical solution described in this invention lies in: This invention controls the eutectoid reaction of FeO and the chemical reaction processes of different ferrous oxides by employing high-temperature rolling, optimizing the hot rolling temperature regime, and controlling the post-rolling cooling rate and coiling temperature, thereby controlling the thickness of the iron oxide scale on the strip surface. Due to the high plasticity and good adhesion of Fe3O4, a continuous isolation layer can be formed between the die and the hot-rolled plate during the stamping process. This isolation layer reduces the coefficient of friction between the die and the plate, thereby reducing friction and providing lubrication, preventing direct contact between the die and the plate, and eliminating the problem of roughening during hot-rolled plate stamping. Simultaneously, an appropriate thickness of iron oxide scale ensures the integrity and stability of the isolation layer; a thickness of 21-24 μm provides sufficient lubrication without causing the iron oxide scale to detach or produce other adverse effects during stamping due to excessive thickness.
[0012] The beneficial effects of adopting the above technical solution are as follows: The method of this invention can eliminate or mitigate the problem of stamping roughening in hot-rolled automotive structural steel, significantly improving the surface quality of automotive parts. A smooth and flat surface not only enhances the appearance of the car, satisfying consumers' pursuit of quality, but also reduces stress concentration caused by surface defects, improves the fatigue resistance of parts, enhances the stability and safety of the automotive structure, and reduces the risk of malfunctions caused by structural problems during driving.
[0013] In terms of cost control, improving the stamping process can reduce the scrap rate. Defective or scrapped products caused by the scrapping process waste raw materials and processing time. Lowering the scrap rate means that raw materials can be used more efficiently, production efficiency is improved, and thus production costs are effectively controlled. At the same time, due to improved product quality, the probability of after-sales repairs and parts replacements is reduced, further saving the company's after-sales costs.
[0014] In terms of production efficiency, optimizing the stamping process to improve the problem of roughening can reduce die wear and damage. Frequent die repairs or replacements due to roughening extend downtime and affect production schedules. Reducing roughening extends die life, lowers die maintenance frequency, makes the production process smoother and more efficient, and improves the company's production capacity and market competitiveness. Attached Figure Description
[0015] Figure 1 The thickness of the iron oxide scale on the steel in Example 1 is shown.
[0016] Figure 2 The thickness of the iron oxide scale on the steel in Example 2.
[0017] Figure 3 The thickness of the iron oxide scale on the steel in Example 3 is shown.
[0018] Figure 4 The thickness of the iron oxide scale on the steel in Example 4.
[0019] Figure 5 The thickness of the iron oxide scale on the steel in Example 5. Detailed Implementation
[0020] The technical solution of the present invention will be further described in detail below through embodiments.
[0021] A method for eliminating stamping roughening of hot-rolled automotive structural steel involves optimizing and controlling the hot rolling, laminar cooling, and coiling processes during steel plate production to form a 21-24mm iron oxide scale on the surface of the automotive structural steel.
[0022] The hot rolling process has a heating temperature of 1180-1260℃; the finishing rolling inlet temperature is 1000-1050℃; and the final rolling temperature is 880-920℃.
[0023] The laminar flow cooling process employs front-end cooling with a cooling rate of 40-60℃ / s.
[0024] The winding process is carried out at a temperature of 580-620℃.
[0025] The process parameters for hot rolling, laminar flow cooling, and coiling of hot-rolled automotive structural steel in each embodiment are shown in Table 1.
[0026] Table 1 Key production process parameters for steel plates in each embodiment
[0027] Examples 1-5 show the thickness of the iron oxide scale on hot-rolled steel plates as follows: Figure 1-5 As shown; by Figures 1-5 It is known that the method of the present invention can form an iron oxide scale with a thickness of 21-23 mm on the surface of a steel plate.
[0028] After the steel plates of each embodiment were stamped into structural parts, there was no roughening problem on the surface.
[0029] The above embodiments are only used to illustrate and not limit the technical solutions of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the present invention without departing from the spirit and scope of the present invention. Any modifications or partial substitutions should be covered within the scope of the claims of the present invention.
Claims
1. A method for eliminating stamping roughening in hot-rolled automotive structural steel, characterized in that, By optimizing and controlling the hot rolling, laminar cooling, and coiling processes in the steel plate production process, a 21-24mm iron oxide scale is formed on the surface of automotive structural steel.
2. The method for eliminating stamping roughening of hot-rolled automotive structural steel according to claim 1, characterized in that, The hot rolling process has a heating temperature of 1180-1260℃; the finishing rolling inlet temperature is 1000-1050℃; and the final rolling temperature is 880-920℃.
3. The method for eliminating stamping roughening of hot-rolled automotive structural steel according to claim 1, characterized in that, The laminar flow cooling process employs front-end cooling with a cooling rate of 40-60℃ / s.
4. The method for eliminating stamping roughening of hot-rolled automotive structural steel according to claim 1, characterized in that, The winding process is carried out at a temperature of 580-620℃.