íshín-308LR has nominal composition (wt. %) of weld metal 19.5 Cr, and 10 Ni which is same as íshín-308, except for the carbon content. The 0.04 percent maximum carbon content of weld metal deposited by these electrodes reduces the possibility of intergranular carbide precipitation and thereby increases the resistance to intergranular corrosion without the use of stabilizers such as niobium or titanium. A carbon content of 0.04 percent maximum has been shown to be adequate in weld metal, even though it is recognized that similar base metal specifications require a 0.03 percent limitation. This low-carbon alloy, however, is not as strong at elevated temperature as íshín-308H or íshín-347.
The covering for these electrodes generally contains readily ionizing elements to stabilize the arc for welding with alternating current. Electrode sizes 4.0 mm and smaller may be used in all positions of welding.
Storage and Drying Conditions: Hydrogen can have adverse effects on welds in some steels under certain conditions. One source of this hydrogen is moisture in the electrode coverings. For this reason, the proper storage, treatment, and handling of electrodes are necessary.
Holding Ovens: 125°C–150°C.
Drying Conditions: 250°C–425°C for 1 hour prior to use.
CHEMICAL COMPOSITION OF UNDILUTED WELD
|
C |
Cr |
Ni |
Mo |
Nb+Ta |
Mn |
Si |
P |
S |
N |
Cu |
Others |
|
0.04 |
18.0-21.0 |
9.0-11.0 |
0.75 |
NS |
0.5-2.5 |
1.00 |
0.04 |
0.03 |
NS |
0.75 |
NS |
Single values are maxima, except where specified otherwise.
ALL-WELD-METAL MECHANICAL PROPERTIES
|
Tensile Strength, MPa |
Yield Strength, At 0.2% Offset, MPa |
Elongation % |
Lateral Expansion, mm |
Charpy V-Notch Impact at NS°C, Joules |
|
520 |
NS |
30 |
NS |
NS |
Single values are minimal.
ELECTRODE SIZE & WELDING CURRENT (AC and DCEP)
|
DIAMETER, mm |
LENGTH, mm |
Amperes |
|
2.50 |
350 |
65-90 |
|
3.15, 3.20 |
350 |
90-120 |
|
4.00 |
350 |
120-150 |
|
5.00 |
350 |
160-200 |
WARNING: Safety and health information is available from many sources, including, but not limited to Safety and Health Fact Sheets listed in A11.3, ANSI Z49.1 Safety in Welding, Cutting, and Allied Processes published by the American Welding Society, 8669 Doral Blvd., Suite 130, Doral, FL 33166., and applicable federal and state regulations. The Safety and Health Fact Sheets are revised, and additional sheets added periodically.
