16 Plain
Carbon and Low Alloy Steels 1.
WELDABLE MATERIALS Two
general types of plain carbon or low alloy steels are ”killed” steel
and ”rimmed” steel. The former is deoxidized
during the refining process; little difficulty is experienced in welding this
type. In the making of rimmed
steel, however, deoxidation is incomplete. When this type of steel is subsequently
melted in the welding
operation, gases are given off and can be a major cause of porosity if proper
care is not exercised. Proper
care can be taken by using ER 70S-2 triple deoxidized wire.
2. WELDING RODS
For welding most low carbon steel,
ER 70S-2 or ER 70S-7 rod is used. For low-alloy high strength steels,
ER 80S-D2 or ER 100S-1, ER 120S-1,
or ER 140S-1 wire can be used. Alloy losses during welding will be
negligible. Thickness
Amperes Suggested
Average (in.)
DCSP Rod
Size Welding Speed
Argon Flow (in.)
(I.P.M.) C.F.H.
0.035 100
1/16 12-15
8-10 0.049
100-125 1
/16 12-18 8-10
0.060 100-140
1/1 6 12-18
8-10 0.089
140-170 3/32
12-18 8-10
0.125 150-200
1/8 10-12
8-10
