In order to ensure the welding quality, the parts of the workpiece that need to be welded before welding can be processed by gas cutting or cutting, which are generally inclined planes and sometimes curved surfaces.
For example, two 10mm thick steel plates should be butt welded together.
In order to make the weld firm, chamfer will be milled on the edge of the plate, which is called beveling.
Due to the difference of material thickness and welding quality requirements, the welding joint form and groove shape are also different.
Generally, the groove form is divided into K-type, V-type, I-type, U-type, X-type, etc.
Geometric dimension of groove
(1) Groove surface
The groove surface on the piece to be welded is called groove surface.
(2) Groove face angle and groove angle
The included angle between the end face of the groove to be processed and the groove surface is called the groove surface angle, and the included angle between the two groove surfaces is called the groove angle.
(3) Root gap
The gap reserved between the root of the joint before welding is called root gap.
Its function is to ensure root penetration during backing welding.
Root clearance is also called assembly clearance.
(4) Blunt edge
When the weldment is beveled, the straight edge of the end face along the root of the weldment joint groove is called a blunt edge.
The function of the blunt edge is to prevent the root from burning through.
(5) Root radius
The fillet radius at the bottom of J-shaped and U-shaped grooves is called the root radius.
Its function is to increase the space at the root of the groove so that the root can be welded through.
Common groove forms
Single side V-groove with blunt edge:
Fig.: single J-groove
Figure: double J-groove
Figure: single U-groove
Figure: Double U-groove