Bending Stainless Steel
Stainless steel can be formed in the same way and using the same type of equipment as for other alloy steel. Some differences in technique apply and these are explained below. The information in this article is specifically directed towards austenitic stainless steel, the most frequently used family of stainless steel.
Austenitic stainless steel exhibit strong work hardening characteristics which affect many of the forming techniques. Machinery power levels need to be increased or existing capability levels down-rated compared with carbon steel. A higher rigidity of tools and machinery is necessary for working stainless steel.
All fabrication processes should be carried out in a cleaning, and if possible, a dedicated environment.
Bending flat material and bars
Stainless Steel Flat sheet/plate and bar products can be bent using the pressure brake or bend machine. The work should be executed as quickly as possible due to work hardening characteristics of stainless steel, and a degree of over bending is necessary to counteract the springback of the bend. Inside radii of bends sharper than a figure equal to the material thickness under consideration should not be attempted.
Tube bending
Numerous architectural and process applications of tubular pipework and bends exist. In the bending of tube, guidelines can be set down, but first hand experience has to be gained to achieve regular reliable results.
Tubes can be bent satisfactorily using Rotary Bending machines, where one end of the straight stainless steel tube is clamped and the machine former rotates to pull the tube to the designed radius. Alternatively, bending in a hydraulic pressure will push a radiused head on to the tube to force the tube into roller dies.
In considering either in-house or sub-contract tube bending, the quantity involved will have a significant bearing, as will the complexity of the final shapes.
Centre-line bend radii of 2 x tube diameter are generally considered to be a minimum for stainless steel materials.
Related References:
1. Heat exchanger Tube
2. Pipe and Tube Bender
3. U Tube heat exchanger
4. U bend Stainless Steel Tube
5. ASTM A556M
6. āUā Bent Cold Drawn Stainless Steel Tube
7. Bend Testing
8. Bend Tubing Happens
9. Bending Stainless Steel
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