Method for determining aluminum-silicon coating hot forming steel production process window

Abstract

The invention discloses a method for determining a production process window of aluminum-silicon coating hot forming steel, which comprises the following steps of: S1, determining various performance indexes of a hot stamping part according to the technical requirements of aluminum-silicon coating hot stamping steel; s2, a plurality of sets of to-be-tested aluminum-silicon coating hot stamping steel test samples are prepared, multiple sets of to-be-tested aluminum-silicon coating hot stamping steel test samples with the same material thickness are arranged, and testing is conducted with the heating temperature and the heating time as variables; s3, completing a corresponding test sample test on a production line according to the process parameters in the S2, and drawing a total process window according to a test result; and S4, according to the total process window in the S3, determining a parameter interval of the heating temperature and the heating time in a range in which each performance index is qualified, and forming a final process window. According to the process parameter matrix provided by the method and the drawn process window, the production parameter process window can be quickly confirmed, and the method is suitable for hot stamping parts with different material thicknesses and different production lines.

Description

Technical Field

[0001] The present invention relates to the technical field of determining hot stamping process parameters, and more specifically, to a method for determining a production process window for hot-formed steel with an aluminum-silicon coating. Background Art

[0002] In recent years, the application of hot stamping on automobile bodies has become mainstream. Commonly used hot stamping products include: front and rear door side anti-collision beams, A-pillar reinforcement plates, B-pillar reinforcement plates, floor center channels, front and rear longitudinal beams and other safety structural parts. These hot-formed products have the characteristics of high strength, good formability, high dimensional accuracy and low springback.

[0003] Generally, the surface state of hot stamping steel is divided into bare plate and coated steel plate. Since coated hot stamping steel plate can save shot peening after hot stamping compared to bare plate, it is becoming more and more widely used. The most commonly used is aluminum silicon coated hot stamping steel.

[0004] The process window refers to the control range of process parameters under the condition of meeting the target requirements. It is of great significance for quickly determining and predicting whether different combinations of process parameters can meet the product performance requirements. At present, in actual production, the determination of production process parameters is more based on experience, that is, trial and error. The applicability of process parameters selected by this method is very poor. Any subsequent changes require re-exploring new process specifications and re-verifying product performance.

[0005] Each hot stamping production line inevitably has differences, and determining its process window is of great significance for the technical guidance of production. The width of its process window also affects the production cost and product performance. In particular, when the heating time window is too short, it will have a greater impact on the part production process. If the hot stamping production line fails and stops, and the troubleshooting time exceeds the allowable sheet heating time, the aluminum-silicon coating will be over-alloyed, resulting in a decrease in the corrosion resistance of the parts, and all the sheets in the furnace have to be scrapped.

[0006] Therefore, it is necessary to study the method of determining the process window of the hot stamping production line so that the determined process parameters have stronger applicability. Summary of the invention

[0007] The purpose of the present invention is to provide a method for determining the production process window of aluminum-silicon coated hot-formed steel. The production parameter process window can be quickly confirmed based on the process parameter matrix proposed by the method and the drawn process window. This method is applicable to hot stamping parts with different material thicknesses and different production lines.

[0008] The technical solution adopted by the present invention to solve this technical problem is: a method for determining the production process window of aluminum-silicon coated hot-formed steel is provided, comprising the following steps: S1: According to the technical requirements of hot stamping steel with aluminum silicon coating, confirm the performance indicators of hot stamping parts; S2: preparing several groups of aluminum-silicon coated hot stamping steel test samples to be tested, wherein multiple groups of aluminum-silicon coated hot stamping steel test samples with the same material thickness are provided, and the test is conducted with heating temperature and heating time as variables; S3: completing the corresponding test sample test on the production line according to the process parameters in step S2, and drawing the total process window according to the test results; S4: According to the total process window in step S3, the parameter range of heating temperature and heating time is determined within the range where all performance indicators are qualified, so as to form a process window that ultimately meets the technical requirements of aluminum-silicon coated hot stamping steel.

[0009] Preferably, in the method for determining the production process window of aluminum-silicon coated hot-formed steel, in step S1, the performance indicators of the hot stamping parts include: hardness, total aluminum-silicon coating thickness and alloy layer thickness.

[0010] Preferably, in the method for determining the production process window of aluminum-silicon coated hot-formed steel, in step S2, in the multiple groups of aluminum-silicon coated hot stamping steel test samples with the same material thickness, the heating temperature is set to increase by 10°C in sequence, and the heating time is set to decrease by 10s in sequence, wherein in each group of test samples with the same heating temperature setting, the heating time is set to increase by 20s in sequence.

[0011] Preferably, in the method for determining the production process window of aluminum-silicon coated hot-formed steel, in step S3, the specific steps of the test sample test include: The aluminum-silicon coated hot stamping steel test samples with different process parameters were placed in a heating furnace for heating. After heating, the test samples were placed in a mold for cooling and forming, and then various performance indicators were measured.

[0012] Preferably, in the method for determining the production process window of aluminum-silicon coated hot-formed steel, the cooling rate of each group of aluminum-silicon coated hot stamping steel test samples put into the mold remains consistent.

[0013] Preferably, in the method for determining the production process window of aluminum-silicon coated hot-formed steel, in step S4, the parameter interval of the final heating temperature and heating time is selected according to the parameter range of the lowest temperature and the shortest time and the highest temperature and the longest time.

[0014] The present invention has at least the following beneficial effects: 1. The process parameter matrix and the drawn process window proposed by the present invention can be used to quickly confirm the production parameter process window. The process window of hot stamping parts with different material thicknesses and different production lines can be confirmed according to this method.

[0015] 2. According to the process window, the production process parameter range can be quickly confirmed, and the residence time of the sheet in the heating furnace can be maximized to reserve time for the production line to handle fault shutdown, avoid batch scrapping of sheets in the furnace, and at the same time avoid a lot of production line debugging time, laboratory experiments, industrial trial and error time, finished product scrapping, etc., thereby saving product development time and reducing development costs.

[0016] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is an example diagram of the total process window in step S3 of a method for determining a production process window for hot-formed steel with an aluminum-silicon coating; Figure 2 This is an example diagram of a process window for ultimately meeting the technical requirements of aluminum-silicon coated hot stamping steel in step S4 of a method for determining a production process window for aluminum-silicon coated hot-formed steel. DETAILED DESCRIPTION

[0018] The present invention is described in detail and completely below in conjunction with the accompanying drawings. A person of ordinary skill in the art will be able to implement the present invention based on these descriptions. Before describing the present invention in conjunction with the accompanying drawings, it should be particularly pointed out that the technical solutions and technical features provided in each part of the present invention, including the following description, can be combined with each other without conflict.

[0019] In addition, the embodiments of the present invention involved in the following description are generally only a part of the embodiments of the present invention, rather than all the embodiments. Therefore, based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0020] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments, and its specific implementation process is as follows: like Figure 1-2 As shown, the present invention provides a method for determining the production process window of aluminum-silicon coated hot-formed steel, comprising the following steps: S1: According to the technical requirements of hot stamping steel with aluminum silicon coating, confirm the performance indicators of hot stamping parts; S2: preparing several groups of aluminum-silicon coated hot stamping steel test samples to be tested, wherein multiple groups of aluminum-silicon coated hot stamping steel test samples with the same material thickness are provided, and the test is conducted with heating temperature and heating time as variables; S3: completing the corresponding test sample test on the production line according to the process parameters in step S2, and drawing the total process window according to the test results; drawing the total process window according to the heating temperature and heating time; S4: According to the total process window in step S3, the parameter range of heating temperature and heating time is confirmed within the range where all performance indicators are qualified, so as to form a process window that ultimately meets the technical requirements of aluminum-silicon coated hot stamping steel; within this process window, the hot stamping parts produced can be guaranteed to meet the process requirements.

[0021] The above method can not only be used to determine the process window of aluminum-silicon coated hot stamping steel on the production line, but also can cover the determination of the process window of bare boards.

[0022] Furthermore, in the method for determining the production process window of aluminum-silicon coated hot-formed steel, in step S1, the performance indicators of the hot stamping parts include but are not limited to: hardness, total aluminum-silicon coating thickness and alloy layer thickness. For example: hardness ≥ e HV, total aluminum-silicon coating thickness a~bμm, alloy layer thickness ≤dμm, etc.

[0023] Furthermore, in the method for determining the production process window of aluminum-silicon coated hot-formed steel, in step S2, the heating temperature of the multiple groups of aluminum-silicon coated hot stamping steel test samples with the same material thickness is set to increase by 10°C in sequence, and the heating time is set to decrease by 10s in sequence, wherein the heating time of each group of test samples with the same heating temperature setting is set to increase by 20s in sequence. The process parameter matrix is ​​shown in the following table: Table 1: Process parameter matrix Furthermore, in the method for determining the production process window of aluminum-silicon coated hot-formed steel, in step S3, the specific steps of the test sample test include: The aluminum-silicon coated hot stamping steel test samples with different process parameters were placed in a heating furnace for heating. After heating, the test samples were placed in a mold for cooling and forming, and then various performance indicators were measured.

[0024] Furthermore, in the method for determining the production process window of aluminum-silicon coated hot stamping steel, the cooling rate of each group of aluminum-silicon coated hot stamping steel test samples put into the mold is kept consistent, so as to overcome the influence of the cooling rate on the final result.

[0025] Furthermore, in the method for determining the production process window of aluminum-silicon coated hot-formed steel, in step S4, the parameter interval of the final heating temperature and heating time is selected according to the parameter range of the lowest temperature with the shortest time and the highest temperature with the longest time. Within this process window, the hot stamping parts produced can be guaranteed to meet the process requirements, and at the same time, the residence time of the sheet in the heating furnace can be maximized, and time can be reserved for the production line to handle fault shutdowns, avoiding batch scrapping of sheets in the furnace, and avoiding a large amount of production line debugging time, laboratory experiments, industrial trial and error time, and losses caused by finished product scrapping, etc., thereby saving product development time and reducing development costs.

[0026] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the embodiments shown and described herein.

Claims

1. A method for determining the production process window of aluminum-silicon coated hot-formed steel, characterized in that: The steps include: S1: According to the technical requirements of hot stamping steel with aluminum silicon coating, confirm the performance indicators of hot stamping parts; S2: preparing several groups of aluminum-silicon coated hot stamping steel test samples to be tested, wherein multiple groups of aluminum-silicon coated hot stamping steel test samples with the same material thickness are provided, and the test is conducted with heating temperature and heating time as variables; S3: completing the corresponding test sample test on the production line according to the process parameters in step S2, and drawing the total process window according to the test results; S4: According to the total process window in step S3, the parameter range of heating temperature and heating time is determined within the range where all performance indicators are qualified, so as to form a process window that ultimately meets the technical requirements of aluminum-silicon coated hot stamping steel.

2. The method for determining the production process window of aluminum-silicon coated hot-formed steel according to claim 1, characterized in that: In the step S1, the performance indicators of the hot stamping parts include: hardness, total aluminum-silicon coating thickness and alloy layer thickness.

3. The method for determining the production process window of aluminum-silicon coated hot-formed steel according to claim 1, characterized in that: In step S2, in the multiple groups of aluminum-silicon coated hot stamping steel test samples with the same material thickness, the heating temperature is set to increase by 10°C in sequence, and the heating time is set to decrease by 10s in sequence, wherein in each group of test samples with the same heating temperature setting, the heating time is set to increase by 20s in sequence.

4. The method for determining the production process window of aluminum-silicon coated hot-formed steel according to claim 1, characterized in that: In step S3, the specific steps of the test sample test include: The aluminum-silicon coated hot stamping steel test samples with different process parameters were placed in a heating furnace for heating. After heating, the test samples were placed in a mold for cooling and forming, and then various performance indicators were measured.

5. The method for determining the production process window of aluminum-silicon coated hot-formed steel according to claim 4, characterized in that: The cooling rate of each group of aluminum-silicon coated hot stamping steel test samples put into the mold is kept consistent.

6. The method for determining the production process window of aluminum-silicon coated hot-formed steel according to claim 1, characterized in that: In step S4, the parameter intervals of the final heating temperature and heating time are selected according to the parameter ranges of the lowest temperature and the shortest time and the highest temperature and the longest time.

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