The common method of stainless steel elbow forming is the push-bending forming process.
Push bending is a common method of bending stainless steel pipe fittings, mainly used for bending elbows. According to the characteristics of the process, it can be divided into cold bending and mandrel hot bending.
1. Cold push bending
Using the bending device to push the bent pipe blank on the ordinary hydraulic press or crank press, the stainless steel straight pipe blank is pressed into the mold with the bending cavity at normal temperature, thereby forming a stainless steel elbow.
Cold push elbows are suitable for stainless steel elbows with a small bending radius. The minimum relative bending radius r / d ≈ 1.3, the ellipse of the elbow section is small (≤3% -5%), and the outer tube wall becomes thinner (≤ 9%) can be bent; the elbow bending device has a simple structure, does not require special equipment, and has high productivity. However, it is generally required that the relative thickness of stainless steel pipe t / d ≥ 0.06, otherwise, the pipe billet will often lose stability due to poor stiffness, causing the inside of the elbow to wrinkle or twist.
2. Hot rod bending
The mandrel type hot push bend pipe is made on a special pushing machine, which is pushed through the horn horn under axial thrust and heated while being heated, so that the tube billet produces circumferential expansion and axial bending deformation, thereby reducing the diameter of the pipe The billet is pushed into a larger diameter elbow.
