Table 5. Permissible Undercut Values

TB9-2510-242-40

c. The welding current, voltage, gas flow, filler metal diameter and travel speed shall be such that each pass will

have complete fusion with adjacent weld metal and base metal. There shall be no overlap, excessive porosity or

undercutting in excess of Table 5.

d. The welder shall employ the forehand technique.

4.1.10 Welding Techniques - Gas Metal Arc Welding (GMAW) with Single Electrode .

The following restrictions on GMAW procedures must be observed at all times.

a. The maximum size of a stringer bead fillet weld make in one pass shall be 1/2 inch for the flat and vertical

positions and 3/8 inch for horizontal and overhead positions.

b. The thickness of weld layers, except root and surface layers shall not exceed inch. When the root opening of a

groove weld exceeds 3/8 inch, a multiple pass split layer technique shall be used. The split layer technique shall

also be used in making all multiple pass welds when the width of the layer exceeds 1/2 inch.

c. The welding current, voltage, gas flow and travel speed shall be such that the arc is in the spray transfer made

and that each pass will have complete fusion with adjacent weld metal and base metal. There shall be no

overlap or excessive porosity or undercutting in excess of the values provided in Table 5.

d. Runoff tabs may be used to break the arc, thus avoiding formation of crater cracks.

e. The progression of all passes of vertical position welding shall be upwards.

f. Welder shall employ the forehand technique. A backhand technique shall be permitted for root pass disposition

when the welder is qualified for that technique

g. Complete joint penetration groove welds make without the use of backing shall have the root of the initial pass

back gouged, chipped or otherwise removed to sound metal, and all trace of root discontinuity shall be eliminated

before welding is started from the second side.

4.1.11 Weld Inspection - Visual . All welds shall be visually inspected. All welds must exhibit the following

characteristics:

no visible cracks in surface of weld or base metal

thorough fusion exists between adjacent layers of weld metal and base metal

all craters filled

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