©
COPYRIGHT 2000 THE ESAB GROUP, INC. LESSON
V
5.22.2
Nickel-Arc
550 (AWS
A5.15,
Class ENiFe-CI-A)
- Nickel-Arc 550 electrode is
made with 55% nickel and 45% iron core
wire. The coating is specially designed to give smooth,
stable arcs on both direct and alternating current. Nickel-Arc 550 is also
designed to provide
superior resistance to overheating, allowing maximum deposition efficiency during
the welding operation.
A. Typical
Properties of
Nickel-Arc
Weld Metal:
Tensile Strength (psi)
58,500 Hardness
across weld in gray iron 90-100
Rb Machinability
Excellent Color
Match Good
5.22.3
Nickel-Arc
99 (AWS
A5.15,
Class ENi-CI)
- Nickel-Arc 99 electrodes are made
with pure nickel core wire. The
high nickel content of the deposited weld metal absorbs the
carbon from the cast iron and remains
tough and ductile. The electrode has good welding characteristics
with smooth stable arc on both direct current and alternating current.
Nickel-Arc 90 produces sound crack-free
welds in gray, malleable and nodular iron. It is particularly
valuable for welding or overlay of cast iron when high nickel deposits are required
or when ease of machining the weld
area is important. Preheat, interpass temperature, and
cooling rate after welding depends
on the type and design of the object to be welded. When
welding cavities in cast iron, wide
weaving and heavy weld beads should be used. Welding
10-20° uphill helps deposit thicker
weld beads that better resist cracking. A.
Typical Properties
of Nickel-Arc
Weld Metal:
Tensile Strength (psi)69,900
Hardness across weld in gray iron
90-100 Rb
Machinability
Excellent Color
Match Good
5.22.4
Nicore
55 (Meets
chemistry requirements
of AWS
ENiFe-CI)
- Nicore 55 is a "wire
within a wire" flux cored electrode
with approximately 50.5% iron and 48% nickel, provid-
ing an excellent match for the coefficient
of expansion exhibited by cast irons. The wire pro-
duces a light slag that is easily removed
enhancing visual weld inspection. 5.22.4.1
Because of the continuous nature of
this wire, operating factor, arc time, and depo- sition
efficiency are all improved over the conventional manual stick electrodes. This
electrode is ideally
suited for the repair and joining of various types of cast irons. The machinability
characteristics are similar to that
of the 55-grade covered electrodes. DC (electrode positive)
is the recommended current.
