Stainless steel is a new type of environmentally friendly material. With its characteristics of corrosion resistance and formability, it has been widely used in the field of auto parts.
En la industria del automóvil, debido a la materia prima de acero inoxidable (placa de acero), todas las carrocerías deben estar conectadas mediante soldadura. Por lo tanto, la soldadura láser juega un papel muy importante en la aplicación del acero inoxidable en la industria automotriz.
Due to the influence of many factors, stainless plates welding have deformation problems and is difficult to control, which will greatly affect the application of stainless plates in the automotive industry. So, what is the countermeasure?
Overview of Laser Welding Stainless Plates
Laser welding mainly refers to a welding method that uses laser energy as a heat source to melt and connect workpieces. In the process of laser welding, the laser irradiates the surface of the material to be welded and affects it. A part of it is reflected and the rest is absorbed into the material to complete the welding target.
In short, the process of laser welding is to use a high-power laser beam focused by the optical system to irradiate the surface of the material to be welded, and then make full use of the material to absorb light energy for heating and other treatments. Finally, the welding joint is formed by cooling. A kind of melting welding process. Under normal circumstances, laser welding is mainly divided into thermal conductivity welding and deep penetration welding.
Los peligros de la deformación de la soldadura y los principales factores que afectan la deformación de la soldadura.
Los principales factores que afectan la deformación de la soldadura son la corriente de soldadura, el ancho de pulso y la frecuencia. A medida que aumenta la corriente de soldadura, también aumenta el ancho del cordón de soldadura, y aparecen gradualmente fenómenos como salpicaduras, que resultan en la oxidación y deformación de la superficie del cordón de soldadura, acompañada de rugosidad; el aumento de la amplitud del pulso aumenta la resistencia de la junta soldada. Cuando el ancho del pulso alcanza un cierto nivel, el consumo de energía por conducción de calor en la superficie del material también aumenta.
The evaporation causes the liquid to splash out of the molten pool, resulting in a smaller cross-sectional area of the solder joint, which affects the strength of the joint; the influence of the welding frequency on the welding deformation of the Placa de acero inoxidable is closely related to the thickness of the steel plate.
Por ejemplo, para una placa de acero inoxidable de 0.5 mm, cuando la frecuencia alcanza los 2 Hz, la tasa de superposición de la soldadura es mayor; cuando la frecuencia alcanza los 5 Hz, la soldadura se quema gravemente, la zona afectada por el calor es más ancha y se produce una deformación. Se puede ver que es imperativo fortalecer el control efectivo de la deformación de la soldadura.
Effective Countermeasures to Avoid Laser Welding Distortion
To reduce the problem of laser welding deformation and improve the welding quality of stainless steel plates, we can start by optimizing welding process parameters. The specific operation methods are as follows:
1. Introducir activamente el método de experimento ortogonal
El método de experimento ortogonal se refiere principalmente a un método matemático-estadístico que analiza y ordena experimentos multifactoriales a través de tablas ortogonales. Puede utilizar menos experimentos para obtener resultados efectivos e inferir el mejor plan de implementación. Al mismo tiempo, también puede realizar análisis en profundidad, obtener información más relevante y proporcionar una base para un trabajo específico.
Generalmente, la corriente de soldadura, el ancho de pulso y la frecuencia del láser se seleccionan como los objetos de observación clave, la deformación de la soldadura se considera un índice y se controla al valor mínimo, y se cumple el principio de razonabilidad, y el nivel del factor es controlado dentro de un rango apropiado. Por ejemplo, para una placa de acero inoxidable con un grosor de 0.5 mm, la corriente se puede controlar entre 80 ~ 96I / A; la frecuencia está entre 2 ~ 5f / Hz, etc.
2. La elección de la mesa ortogonal
En circunstancias normales, el número de niveles de factor de prueba debe ser coherente con el número de niveles en la tabla ortogonal y el número de factores debe ser menor que el número de columnas en la tabla ortogonal. Un diseño razonable de la mesa ortogonal puede proporcionar el apoyo y la ayuda correspondientes para el trabajo de investigación posterior.
3. Análisis de resultados de pruebas extremadamente deficientes
Through the test results of the stainless plates with a thickness of 0.5mm, the range of each column is not equal, which proves that the different levels of each element are unique, and the impacts are also different. The effects on the laser welding deformation are current, pulse width, and Frequency, comprehensive factors, the best laser welding process parameters should control the current to 85A, the pulse width is 7ms, and the frequency is 3Hz. Controlling the welding process parameters to three values can ensure the smallest welding deformation of the 0.5mm stainless steel plates.
For stainless plates with a thickness of 0.8mm, when the deformation is minimized based on meeting the tensile strength of the weld, the parameters such as current, pulse width, and frequency should be controlled at 124A, 8ms, and 4Hz respectively. The stainless steel plates with a thickness of 1mm are 160A, 11MS, and 5Hz respectively. In the laser welding process, the welder controls various parameters within a reasonable range, which not only improves the welding quality and efficiency but also avoids the deformation of the steel plate and meets the production requirements.
With the rapid development of science and technology, the technology of controlling welding deformation has also developed, such as the application of finite element simulation in welding deformation control, etc., by using welding temperature and stress to avoid welding deformation problems, improve the stress balance of stainless steel plates, and avoid steel plates. Welding deformation can also improve welding quality, thereby promoting the healthy development of related fields.
En conclusión
As an effective welding technology, laser welding technology plays an active role in improving welding quality. However, due to the influence of factors such as laser current, laser welding of stainless plates has problems such as deformation. In this regard, welders can take the orthogonal experiment method to obtain the best process parameters of different thickness steel plates, combine the parameters to perform welding work, and continuously improve the welding quality, to minimize the occurrence of steel plate deformation.