General
Description
Joint
Design &
Preparation
Making the
Weld
Operating
Hints &
Procedures
Definition of
Supporting
Molten Metal
Edge
Preparation
Terms
Joint Cleaning
Basic Joint
Types
23 Edge Preparation by Beveling or Grooving a. Effect of Edge Bevel or Groove The effect of edge beveling or grooving is to control the amount of weld reinforcement (see Fig. 10). The amount of weld penetration is also affected by changes in bevel depth and volume. For butt, fillet and multipass welds, the maximum weld width should be at least somewhat wider than the weld depth. A ratio of 1.25 to 1.5 weld width/weld depth is preferred to reduce the possibility of center weld cracking. Proper joint bevels and proper welding parameter selection assist in obtaining this relationship. b. When to Bevel or Groove Beveling or grooving is especially desirable for butt joints thicker than 5/8 in. Beveling is sometimes used for material as thin as 1/4 in. where it can assist in tracking the weld seam with knife edged wheel followers. In positioned tee joint or comer joint fillet welding where complete root penetration is desired, the abutting member is generally bevelled if the depth of fusion desired for each weld exceeds 3/8-in. c. Effect of Root Face Dimension The unbeveled root face should be thick enough for the weld to fuse down into but not through the butted root faces, or “nose” of the joint. If the thickness of the nose is inadequate, there will not be enough metal mass to absorb the heat of the molten metal and it may spill out of the bottom of the joint. See Fig. 11. d. Methods of Edge Preparation 1. Flame or Plasmarc Cutting - may be done manually or with flame planers or cutting machines. Refer to your ESAB Representative for a description of plate edge preparation techniques and equipment supplied by ESAB. All loose scale and slag resulting from cutting must be removed before assembly and welding. It is not necessary to remove the oxide film formed on cooling; in fact, it is good practice to allow this oxide film to remain on the edges if the plates are to be stored for some time before welding since it will assist in preventing rusting.