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Choosing Stick Electrodes for Welding Cast Iron
by Lincoln's Cast Iron Expert, Joe Kolasa
Joe Kolasa |
Within the walls of The Lincoln Electric
Company are some of the brightest minds in welding, but we wouldn't be The
Welding Experts® if it weren't for the expertise of our customers. Learn
with us from questions submitted by real customers and answered by the real
experts. |
When do I use Lincoln SoftweldŽ 99 Ni, 55 Ni and FerroweldŽ
electrodes?
Choosing electrodes for welding cast iron typically comes down to three things:
cost, machine-ability, and whether the weld is single or multiple pass.
Softweld 99 Ni (AWS class ENi-CI) is a nominally 99% Nickel electrode. Nickel
is expensive, and so, therefore, is this premium electrode. The electrode
will deposit welds that are machine-able, an important consideration when the
casting is to be machined after welding. Repairs made with Softweld 99 Ni are
often single pass welds with high admixture. Even with high admixture, the weld
deposit will remain machine-able. It works best on castings with low or medium
phosphorous contents.
Softweld 55 Ni (AWS class ENiFe-CI)is a nominally 55% Nickel electrode. The
lower Nickel content makes this electrode more economical than Softweld 99 Ni.
Weld deposits are usually machine-able, but under conditions of high admixture,
the welds can become hard and difficult to machine. It is often used for repairing
castings with heavy or thick sections. As compared to Softweld 99 Ni, welds
made with 55 Ni are stronger and more ductile, and more tolerant of phosphorous
in the casting. It also has a lower coefficient of expansion than 99 Ni, resulting
in fewer fusion line cracks.
Ferroweld (AWS class ESt) is a lower cost, steel electrode. The weld deposits
are hard, and are not machine-able, but can be finished by grinding. This is
the lowest cost electrode for welding cast iron, and the electrode has a very
user-friendly arc. It can tolerate welding on castings that cannot be completely
cleaned before welding. Ferroweld deposits will rust, just like cast iron. This
may be important when repairing cast iron parts such as exhaust manifolds on
antique cars.
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