CHARACTERISTICS & APPLICATIONS
íshín-309NB has nominal composition (wt. %) of weld metal 23.5 Cr, 13 Ni which is same as Type 309, except for the addition of niobium and a reduction in the carbon limit. The niobium provides resistance to carbide precipitation and thus increases intergranular corrosion resistance and provides higher strength in elevated-temperature service. E309Nb electrodes are also used for welding Type 347 clad steels or for the overlay of carbon steel.
These electrodes are usable with dcep (electrode positive) only. While use with alternating current is sometimes accomplished, they are not intended for use with this type of 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 |
| 0.12 | 22.0-25.0 | 12.0-14.0 | 0.75 | 0.70-1.00 | 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 |
| 550 | NS | 30 | NS | NS |
Single values are minimal.
ELECTRODE SIZE & WELDING CURRENT (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.