What will be the deformation of seamless steel pipe when air drawing?

After air drawing, the surface area of the outer surface of the seamless steel pipe increases, the surface area of the inner surface decreases, and a neutral layer is required between the inner and outer layers. After the deformation of the layer between the outer surface and the neutral layer, all the surface area increases, and the outer surface layer increases relatively more. After each layer between the neutral layer and the inner surface is deformed, the surface area decreases, while the inner surface decreases more. Divide both sides by D to obtain this formula.

The above changing characteristics of the surface area of each layer of seamless steel pipe during air drawing affects the unevenness of metal deformation. One of its characteristics is that the natural extension of each layer along the pipe wall is inconsistent.

The natural extension treats the outer surface layer of the seamless steel pipe as smaller and the inner surface layer of the seamless steel pipe as larger. There is a gradual increase from the surface layer to the inner surface layer. Another feature is that due to integrity, each layer of the seamless tube steel pipe cannot have a different extension during deformation, and therefore, each layer needs to contain each other. In practice, seamless pipe steel tubes are mainly used for high-precision structural lightweight piping, such as cracking tubes for petrochemical choices, drilling tubes for petroleum geological choices or seamless tubes for use in automobiles and tractors. They all have certain high precision requirements.

Seamless Pipe Factory, Seamless Pipe Manufacturers tell you that Seamless Pipe Since the natural extension of the metal between the outer surface and the neutral layer (called the outer layer) is less than the natural extension of the metal between the neutral layer and the inner layer (called the inner layer), the outer layer needs to be dragged by the inner layer In the deformation process. The actual extension of the seamless tube is greater than the natural extension and its thickness decreases due to the increase in extension. On the contrary, the extension of the inner layer of the seamless tube is hindered by the outer layer, its actual extension is less than the natural extension, and its thickness increases.