How To Bending High Tensile Strength Plate

How To Bending High Tensile Strength Plate


Conventional steels bending degree of strength traditionally haven’t been bent or formed in the high-strength condition; when you are planning to bending one high strength sheet mteal profiles, you could be consider how to choose and set for your press brakes and bending tools:

Bending Material
* Metal Bending force, springback force and the risk of cracking all increase with material strength. Each issue requires individual attention.

* Springback is much greater – often 10 to 25 degrees due to different high tensile strength material, as opposed to the 2.5 to 3 degrees typical with mild steel. And springback varies widely with the different types of material.

* Material cleanliness is important. It should be free of rust, shot-blasted, cleaned and oiled.

* Sheet Cut edges should be deburred.

* Material better  be bent at room temperature. Cold material makes problems worse.

* Material has a stronger tendency to crack in both grain directions than mild steel. It should be bent at right angles to the rolling direction (across the “grain”) to minimize cracking.

Bending Tooling
* At the higher levels of metal bending springback, U-shaped, versus V-shaped dies may be required.

* Across the grain, the bending die V-opening requirement will vary somewhat with the material, but it’s in the range of thickness x 7 to thickness x 16. Punch radius will be in the range of thickness x 1.5 to thickness x 8.

* Bending with the grain, die V-opening should be from thickness x 9 to thickness x 18. Punch radius will be from thickness x 2 to thickness x 8.

* The bending die shoulder radius should be at least one half the plate thicknesses, and it should be hardened and polished. The die shoulder radii must be cleaned and lubricated before each use.

* It’s less likely to crack if press brakes ram speeds are reduced. These materials are strain-rate sensitive; they needs time to flow. In problem cases, we tell the user to slow down to approximately 10% of full speed, and the problem goes away.