Plate Beveling Applications
Applications that require beveling of a metal plate include:
- Surface preparation for welded seam such as a J bevel or V-groove butt weld or other similar joint.
- Deburring to remove slag, dross, and burr.
- Edge-conditioning for cosmetic reasons.
Alternative methods include grinding, chipping, cutting (oxyacetylene, laser, and waterjet). These can result in a surface condition that is less than optimal for the intended application. Any high heat input method will result in some level of metallurgical transformation, and possibly surface oxidation and decarburization. Steels with more than 35 percent carbon will require preheating in order to prevent cracking during flame beveling.
Older style hand-held manual bevel machines require the operator to constantly hold the machine against the edge of the plate while, at the same time, push the machine forward along the workpiece. Operator fatigue can lead to less than ideal bevel throughout the length of the plate.
Modern self-propelled or automatic feed and portable bevel machines machines can process both the top and bottom of plate edges with minimal operator oversight. The self-guiding beveling machines attach directly to the plate in order to traverse plate edges of unlimited lengths. You can flip the plate over in order to bevel both sides, but in some production environments this can be difficult due to the size / weight of the plate. Some beveling machines are designed to machine a reverse bevel on the plate (a bevel on the downside of the plate), eliminating the need to flip the plate over in order to bevel both sides, or the bottom side if that is the preferred workpiece orientation for the manufacturing process.
Beveling for Weld Preparation
The length of the bevel or "land" is the amount of material removed to allow the weld bead to be laid into the materials. This is typically measured by the hypotenuse of the triangle viewed from the end of the plate.
A J bevel is chosen over a V bevel when the strongest plate butt joint is required. The U weld (created by two J bevels) results in a smaller heat-affected zone (HAZ), and reduces the total weld filler required in comparison to a V bevel.
Square butt joints may require a single (welded from one side), or a double (welded from both sides) bevel, depending on the weld specification and the application. Double-groove weld joints typically require less filler material than single-grove joints, reducing heat input and the HAZ and thermal distortion.
Image original source: Benrunge [Public domain], from Wikimedia Commons