N-18

Specification
AWS Specification: AWS A5.1 E7018
JIS Specification: D5016
Other Specification: DIN E5153B10
Description
  • N-18 is an iron powder low hydrogen type electrode containing a large amount of iron powder in coating flux to give higher deposition rates
  • Deposited metal gives excellent mechanical properties, crack resistance, and X-ray quality
  • Good weldabilities, such as smooth and stable arc, easy slag removal, low spatters, and nice bead appearance        

 

TYPICAL CHEMICAL COMPOSITION OF ALL WELD METAL DEPOSITS (%):

C

Si

Mn

P

S

0.07

0.60

0.97

0.013

0.010



TYPICAL MECHANICAL PROPERTIES OF ALL WELD METAL DEPOSITS:
Yield Point
N/mm2 (KSI)
 
Tensile Strength
N/mm2 (KSI)
 
Elongation
%
 
Impact Value
°C, J (°F, Ft-Lbs)
 

510  (74)

590 (86)

29

-29°, 160  (-20°, 118)



TYPICAL DIFFUSIBLE HYDROGEN OF WELD METAL:
Diameter (mm)
 
Current (amp)
 
Re-drying Condition
 
Diffusible Hydrogen Mean Value
(cc./100g)
 

4.0

AC

350ºC x 0.5 hrs.

3.0



SIZE AND RECOMMENDED CURRENT RANGE: AC, DC (+)

DIAMETER (mm)

2.5

3.2

4.0

5.0

6.0

LENGTH (mm)

350

350

400

450

450

Current Amp

Flat

70 - 100

100 - 140

150 - 200

190 - 240

250 - 320

Vertical & Overhead

60 - 90 

80 - 120

120 - 160

140 - 180


Welding Positions: ALL POSITIONS EXCEPT VERTICAL DOWN
Approvals: ABS, BV, DNV, LRS

NOTE:

The information contained or otherwise referenced herein is presented only as “typical” without guarantee or warranty, and Industrial Welding Corporation expressly disclaims any liability incurred from any reliance thereon. Typical data and test results for mechanical properties, deposit, or electrode composition and other properties were obtained from a weld produced and tested according to prescribed standards and should not be assumed to be the expected results in a particular application or weldment. Actual results will vary depending on many factors, including, but not limited to, weld procedure, plate chemistry and temperature, weldment design, and fabrication methods. Users are cautioned to confirm by qualification testing, or other appropriate means, the suitability of any welding consumable and procedure before use in the intended application.

  • All position welding of 50 KG/mm2 high tensile strength steels
  • Ships
  • Steel frames
  • Bridges
  • Pressure vessels

 

  • N-18 stick electrodes require a drag to 1/16 inches maximum arc length to obtain the desired mechanical properties and weld quality
  • An arc length of 1/8 inches or longer may result in porosity and serious deterioration of impact properties
  • Take the backstep method or strike the arc on a small steel plate prepared for this particular purpose to prevent blowholes at the arc starting
  • Polarity: Use DC(+) whenever possible, with 5/32 inches and smaller sizes. Use AC with the larger sizes for the best operating characteristics (min. O.C.V. 70 Volts), but DC(+) can also be used
  • Downhand: On the first pass, or whenever it is desirable to reduce admixture with abase metal of poor weldability, use low currents. On succeeding passes, use currents that provides best operating characteristics. Drag tip electrode lightly or hold as short an arc as possible, 1/16 inches maximum when optimum impacts and X-ray quality are required. Do not use a long arc at any time because this type of electrode relies principally on molten slag for shielding. Stringer beads or small weave passes are preferred to wide weave passes. Layers should be kept as thin as possible (3/16 inches max.) for best properties. When starting a new electrode, strike the arc ahead of the crater, move back into the crater, and then proceed in the normal direction. Use higher currents on AC than DC. Govern travel speed by the desired bead size
  • Vertical: Weld vertical-up with 5/32 inches and smaller sizes. Use a triangular weave for heavy single-pass welds. For multi-pass welds, first deposit a stringer bead using a slight weave. Deposit additional layers with a side-to-side weave, hesitating at the sides long enough to fuse out any small slag pockets and to minimize undercut.
  • Do not use a whip technique or take the electrode out of the molten pool. Travel slow enough to maintain the shelf without causing metal to spill. Use currents in the low to middle portion of the range, depending on joint design and plate thickness
  • Overhead: Use 5/32 inches and smaller electrodes. Deposit stringer beads using a slight circular motion in the crater. Motions should be slow and deliberate. Move fast enough to avoid spilling weld metal, but do not be alarmed of some slags spills. Use currents in the lower portion of the range.

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