阅读说明：本技术 一种1800MPa级超高强度热成形钢板电阻点焊工艺 (Resistance spot welding process for 1800 MPa-level ultrahigh-strength hot-formed steel plate ) 是由 刘岩 叶海青 姚宇 刘佳朋 周桂申 于 2019-08-08 设计创作，主要内容包括：一种1800MPa级超高强度热成形钢板电阻点焊工艺,涉及一种高强度钢板点焊工艺,本发明将两块超高强度热成形钢搭接在一起,并用夹具加紧,使用电阻点焊机器人示教面板,设置路径调整电极位置,使焊接部位位于搭接部分中心点,在示教面板上加入焊接指令并改变焊接压力,通过焊机调整焊接参数后,输入焊接指令完成一次焊接过程,形成电阻点焊接头。本发明提供了一种能够完善超高强度热成形钢板的制造加工技术,使用本发明可以使超高强度热成形钢板在生产制造中有利地结合在一起,从而显著提高产品的综合性能。(The invention discloses a resistance spot welding process for an 1800 MPa-level ultrahigh-strength thermoformed steel plate, which relates to a high-strength steel plate spot welding process. The invention provides a manufacturing and processing technology capable of perfecting ultrahigh-strength hot-formed steel plates, and the ultrahigh-strength hot-formed steel plates can be favorably combined together in production and manufacturing by using the technology, so that the comprehensive performance of products is obviously improved.)

1. The utility model provides a resistance spot welding process of 1800MPa level superhigh strength thermoforming steel sheet, a serial communication port, the technology includes through the pickling under clean experimental environment, carries out the rust cleaning to panel, then gets rid of the oxide layer on surface through polishing, and the reuse acetone is handled the panel surface, guarantees the clean pollution-free in panel surface, then places the panel overlap joint in resistance spot welding robot's on the machine tool, uses robot teaching panel to carry out welding parameter and adjusts to accomplish the welding.

2. The resistance spot welding process for the 1800MPa grade ultrahigh strength hot formed steel plate according to claim 1, wherein the resistance spot welding robot comprises an upper electrode and a lower electrode, wherein the area of the end surface of the upper electrode is the same as that of the end surface of the lower electrode;

The method specifically comprises the following steps: the ultra-high strength hot forming steel plate is placed on a working machine tool of a resistance spot welding robot in a lap joint mode, the lower electrode tip of the welding tongs of the robot is adjusted through the teaching panel to be located at the center of the lap joint part and adjust the pressure of the welding tongs, welding current and welding time are adjusted through the parameter panel of the welding machine, then program setting and control are carried out through the teaching panel of the robot, a welding process is completed, and a spot welding joint is formed.

3. The resistance spot welding process for an 1800MPa grade ultrahigh strength hot formed steel plate according to claim 1, wherein the welding current is adjusted according to the thickness of the steel plate to be welded, and the thicker the steel plate is, the larger the welding current is.

4. the resistance spot welding process of an 1800 MPa-grade ultrahigh-strength hot-formed steel plate as claimed in claim 1, wherein the welding current is 5.5-12.5kA, the welding time is 5-30 cycles, and the electrode pressure is 2000-4000N.

5. The resistance spot welding process of an ultra-high strength hot formed steel plate at 1800MPa according to claim 1, wherein the resistance spot welding robot is DX200, the robot welding gun is FRG-100, the rated power is 100kVA, the secondary current is 7700A, the secondary maximum short circuit current is 20kA, and the maximum pressure of the motor is 400 kgf.

Technical Field

The invention relates to a spot welding process for a high-strength steel plate, in particular to a resistance spot welding process for an 1800 MPa-grade ultrahigh-strength hot-formed steel plate.

Background

The ultra-high strength steel is the development trend of automobile materials in the future. Although light materials such as aluminum alloy, magnesium alloy and carbon fiber are also applied in the current automobile manufacturing, the light materials are not high in neutral price ratio in the manufacturing process due to the defects of the light materials, such as high manufacturing cost, poor corrosion resistance and the like, so that the steel materials are used as main raw materials in the automobile manufacturing. It has been found that if the mass of the car is reduced by 100kg, this means that over 300L of fuel is saved in the course of 150000km, which greatly reduces the use of energy and the emission of pollutants. The ultrahigh-strength hot-formed steel plate with the thickness of 1.0-2.5mm plays an important role in automobile manufacturing, and the safety performance of the automobile is improved while the weight of the automobile is reduced.

The common welding process of hot formed steel at present is mainly laser welding and resistance spot welding. The laser welding has the defects of high assembly requirements, difficult welding of high-reflectivity materials (such as aluminum and copper), high investment cost and the like. The resistance spot welding equipment and the production cost are low, the forming performance is good, the automation degree is high, the range of the weldable workpiece is wide, the welding process of the resistance spot welding can more quickly popularize newly developed steel into the manufacturing of a body-in-white, and the application of new materials on automobiles and the development of light weight of the automobiles cannot be restricted.

The application rate of the ultra-high strength steel on the vehicle body is larger and larger, but the welding performance is poorer and poorer along with the increase of the strength of the ultra-high strength steel. The ultrahigh-strength hot-formed steel has the advantages that under the rapid cooling condition of resistance spot welding, the tendency that the welded spot produces hardened tissues is greatly increased, the problems that the welded joint is broken in the machining process, and the like can be caused, so that the production efficiency of enterprises is influenced, the rejection rate is increased, and the yield of the enterprises is greatly reduced. Therefore, the systematic research on the resistance spot welding process of the ultrahigh-strength hot forming steel has certain theoretical and practical values.

Disclosure of Invention

The invention aims to provide a resistance spot welding process for an 1800 MPa-grade ultrahigh-strength hot-formed steel plate. The problem of resistance spot welding when this kind of superhigh strength hot forming steel sheet is applied to car production is solved, guarantee the quality of this type of welded joint.

The purpose of the invention is realized by the following technical scheme:

The utility model provides a resistance spot welding process of 1800MPa level superhigh strength thermoforming steel sheet, technology includes through the pickling under clean experimental environment, carries out the rust cleaning to panel and handles, then gets rid of the oxide layer on surface through polishing, and the acetone that reuses is handled the panel surface, guarantees that the panel surface is clean pollution-free, then places the panel overlap joint in resistance spot welding robot's work machine tool on, uses robot teaching panel to carry out welding parameter and adjusts to accomplish the welding.

The resistance spot welding process for the 1800 MPa-level ultrahigh-strength hot-formed steel plate comprises an upper electrode and a lower electrode, wherein the area of the end face of the upper electrode is the same as that of the end face of the lower electrode;

the method specifically comprises the following steps: the ultra-high strength hot forming steel plate is placed on a working machine tool of a resistance spot welding robot in a lap joint mode, the lower electrode tip of the welding tongs of the robot is adjusted through the teaching panel to be located at the center of the lap joint part and adjust the pressure of the welding tongs, welding current and welding time are adjusted through the parameter panel of the welding machine, then program setting and control are carried out through the teaching panel of the robot, a welding process is completed, and a spot welding joint is formed.

The resistance spot welding process for the 1800 MPa-level ultrahigh-strength hot-formed steel plate is characterized in that the welding current is adjusted according to the thickness of the welded steel plate, and the thicker the steel plate is, the larger the welding current is.

The resistance spot welding process for the 1800 MPa-level ultrahigh-strength hot-formed steel plate has the advantages that the welding current is 5.5-12.5kA, the welding time is 5-30 cycles, and the electrode pressure is 2000-4000N.

The 1800 MPa-grade ultrahigh-strength hot-formed steel plate resistance spot welding process is characterized in that the model of a resistance spot welding robot is DX200, the model of a welding gun of the robot is FRG-100, the rated power is 100kVA, the secondary current is 7700A, the maximum short-circuit current of the secondary is 20kA, and the maximum pressure of a motor is 400 kgf.

The invention has the advantages and effects that:

The invention adopts the resistance spot welding process, adjusts various welding process parameters and improves the process environment in the welding process, ensures that the welding spot is well formed, has no macroscopic defect, and has all performances reaching the production application standard.

the welding method and the welding process can solve the problem of resistance spot welding when the ultrahigh-strength hot-formed steel plate is applied to automobile production, and ensure the quality of the welded joint.

drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the embodiments or the description of the prior art will be briefly described below, and the drawings in the description are only a part of the embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a schematic illustration of the present invention in sheet lap joint;

FIG. 2 is a schematic view of the welding point of the present invention. The central circle in the figure is a welding spot;

FIG. 3 is a diagram illustrating the welding effect of the plates after the welding of the plates according to the embodiment.

Detailed Description

The present invention will be described in detail with reference to examples.

According to the invention, two ultrahigh-strength hot-formed steel plates are lapped on a working machine tool of a resistance spot welding robot, and parameters are adjusted through a teaching panel for welding. The ultra-high strength hot forming steel is the same steel type and has the same thickness. The resistance spot welding robot uses electrodes of the same type, the end surfaces have the same area, and the method specifically comprises the following steps: the welding device is characterized in that two pieces of ultrahigh-strength thermoformed steel are connected in a lap joint mode and are clamped by a clamp, a teaching panel of a resistance spot welding robot is used, the position of a path adjusting electrode is arranged, a welding position is located at the central point of the lap joint part, a welding instruction is added to the teaching panel, welding pressure is changed, after welding parameters are adjusted through a welding machine, the welding instruction is input to complete a welding process, and a resistance spot welding joint is formed.

in the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. It will be apparent, however, to one skilled in the art, that the present invention may be practiced without one or more of these specific details. In other instances, well-known features have not been described in order to avoid obscuring the invention.

In order to thoroughly understand the present invention, the present invention will be described in detail in the following description with reference to specific examples in order to explain the technical solution of the present invention, and the specific examples of the present invention are described in detail as follows, however, the present invention may have other embodiments in addition to the detailed description.

The invention provides a resistance spot welding process for an 1800 MPa-grade ultrahigh-strength hot-formed steel plate, which uses a hot-formed steel sheet with the length of 100mm, the width of 25mm and the thickness of 1.2mm for welding, and the implementation process comprises the following steps:

1. Performing pretreatment on the hot-formed steel sheet before welding: removing a rust layer on the surface of the steel plate after heat treatment by pickling, removing an oxide layer by polishing, and cleaning a part to be welded by acetone to ensure that the part to be welded is clean;

2. Placing the ultrahigh-strength hot-formed steel sheet on a workbench of a DX200 welding machine in an overlapping manner, wherein the overlapping manner is shown in figure 1, the width of the overlapping part of the steel sheet is 25mm, and clamping by using a clamp to ensure that no gap exists between the steel sheets;

3. The welding current is 12.5kA, the welding time is 10 cycles, and the electrode pressure is 2500N;

4. Adjusting welding current and welding time through a welding machine parameter panel, moving the welding tongs position through a robot teaching panel, ensuring that the welding position of the welding tongs is in the central part shown in figure 2, and adjusting electrode pressure;

5. The welding current of the welding machine parameter panel is adjusted to be 12.5kA, and the welding time is 10 cycles.

6. The teaching panel adjusts the electrode pressure to 2500N;

7. And controlling the robot to complete a welding process through a welding program of the teaching panel to form a welding spot.

8. After the welding of the embodiment, the obtained welding line is shown in fig. 3, the single-point tensile shear strength reaches 15.97kN, the diameter of the nugget of the welding point reaches 5.7mm, and the diameter exceeds the qualified requirement (the diameter is 3 mm) of the product. The nugget is uniform and beautiful.

The embodiments of the present invention have been described above. It is to be understood that the invention is not limited to the particular embodiments described above, in that devices and structures not described in detail are understood to be implemented in a manner common in the art; those skilled in the art can make many possible variations and modifications to the disclosed embodiments, or modify equivalent embodiments, without affecting the spirit of the invention, using the methods and techniques disclosed above, without departing from the scope of the invention. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention are still within the scope of the protection of the technical solution of the present invention, unless the contents of the technical solution of the present invention are departed.