What will be deformed when ASME SA179 seamless steel tube is drawn out

The outer surface area of ASME SA179 seamless steel tube is increased after the empty drawing, and the inner surface area is reduced, and there will be a neutral layer between the inner and outer surface layers. The surface area is increased after the deformation of the outer surface and the neutral layer, and the outer surface layer increases most, and the deformation between the neutral layer and the inner surface is deformed. The area of the back surface is reduced to the maximum.

The above changes of the surface area of ASME SA179 seamless steel tubes affect the inhomogeneity of metal deformation. One of its characteristics is that the natural extension along the wall of SA179 tube wall is not consistent, and the outer surface layer of the SA179 seamless steel tube is the smallest, and the inner surface layer of the SA179 seamless tube is the largest, and the natural extension of the middle layers increases gradually from the surface layer to the inner surface layer. The second characteristic is that due to the overall relationship, the different layers of ASME SA179 seamless steel tube can not be extended during deformation. Therefore, it is necessary for each layer to restrain each other.

Because the natural extension of the metal between the ASME SA179 seamless steel tube outer surface and the neutral layer is smaller than that of the metal between the neutral layer and the inner layer, the outer layer is bound to be affected by the inner layer, and its actual extension is larger than that of the natural extension, and the thickness of the extension is reduced. On the contrary, the extension of the inner layer is hindered by the outer layer, and its actual extension is smaller than the natural extension, and the thickness is increased.