ENi-CI is a nearly pure nickel electrode designed for gray cast-iron repairs where you want a soft, very machinable deposit and low cracking risk—ideal for cold repairs, short beads, and buttering. ENiFe-CI is nickel-iron (≈45% Fe), giving a stronger, harder weld with better dilution tolerance and color match to cast iron; it’s preferred for higher-strength joints, multi-pass work, or joining cast iron to steel. Trade-off: ENi-CI → best machinability; ENiFe-CI → higher strength but less machinable.

What Each Ingredient Does 

Core wire (NiFe 45 — DIN 17745, Werkstoff 2.4472)

• Role: Nickel–iron core (≈55–62% Ni, 38–45% Fe) balances crack resistance + strength and tolerates dilution into cast iron and steel.

• Effect on weld: Stronger and harder than ENi-CI deposits yet still reasonably machinable; better color match to cast iron.

• Impurity limits (C, Mn, Si, S, Cu) kept low to minimize hot cracking, porosity, and brittleness.

Coating powders (fillers & fluxes)

• Zircon (ZrSiO₄): High-melting slag former → smooth bead, glassy protective slag, porosity control. 

• Calcium carbonate (CaCO₃): Gives CO₂ shielding; CaO raises basicity, helps desulfurize/dephosphorize, improves slag release.

• Barium carbonate (BaCO₃): Strong arc stabilizer and hydrogen scavenger; buffers moisture effects. 

• Fluorspar (CaF₂): Fluxing/ionizing agent; lowers slag melting point, increases fluidity, aids desulfurization. 

• Micaceous iron oxide: Plate-like oxide that shapes bead, moderates arc heat, and helps slag peel. 

• Ferro-Titanium 45%: Powerful deoxidizer/denitrogenizer; refines grain, reduces porosity and hot cracking, improves fusion on CI/steel.

• Graphite (natural crystalline): Adds controlled carbon for cast-iron compatibility and machinability; lubricates arc, improves wetting/smoothness. 

• Nickel powder: Tunes deposit toward Ni-Fe target chemistry, boosting ductility and crack resistance vs iron-rich deposits. 

Binders (liquid/organic)

• Sodium silicate: Primary binder—green strength and adhesion; contributes alkali that aids easy striking/re-strike and helps glass the slag. 

• Potassium silicate: Similar bonding with stronger arc ionization (K⁺ favors stable arcs), improving AC performance and start ability.

• Cellulose (HEC or similar): Rheology modifier for smooth extrusion and anti-sag; burns off to create gas channels that steady the arc. 

The Ni-Fe core delivers strength and dilution tolerance; the powder blend controls arc, chemistry, and slag behavior; and the silicate/cellulose binders hold the coating and fine-tune ignition and handling—together giving ENiFe-CI its tougher, reliable performance on cast iron.

The production workflow for these two electrode types does not differ from conventional SMAW electrodes. For a detailed review of the standard process, see [Article 1] and [Article 2].

Below are several points specific to these electrodes that manufacturers should consider.

As outlined elsewhere on this site, SMAW electrodes are produced using either screw or hydraulic extruders. For this specific electrode type, production is feasible only with a hydraulic extruder. Thanks to lubricants such as graphite, talc, and Natrosol, extrusion is straightforward. However, these electrodes are highly prone to cracking; avoid thermal shock during ambient drying and oven baking by using controlled heating.

The AWS A5.15 Standard specifically specifies which tests should be used to determine the quality of these two types of electrodes. Table 2 on page 4 states that the only test required for these two types of products is chemical analysis.

Another important point is that this standard does not require chemical analysis for these two electrodes, and it is only required for the Est electrode.

To test ENi-CI and ENiFe-CI under AWS A5.15, you first make a small weld pad exactly like the standard shows, then take metal shavings from the clean, undiluted weld metal and do a chemical analysis. If the chemistry matches the limits for the class you’re making (ENi-CI or ENiFe-CI), you’ve passed the core requirement.  

The manufacturers of these two types of electrodes, in addition to the chemical analysis of the weld metal, also state mechanical properties for them. The standard also states these specifications on page 18, Table 1A. Although these properties are optional, in order to compete with other manufacturers, it is necessary to examine these properties and state them in the product certificate.

Welding cast iron often presents problems because, unlike steel, it contains high amounts of carbon, phosphorus, and silicon, and it lacks elasticity. It is recommended that, before welding, the surface be cleaned of paint, oil, rust, and other contaminants. Cracks that may form due to thermal stresses in cast iron or due to weld bead contraction can be mitigated by using intermittent (skip) welding and stopping the weld several times.

Light peening on 2-centimeter beads immediately after welding is beneficial. The workpiece at the weld area should never become hotter than what can be comfortably tolerated by hand. In general, use the lowest practical current, avoid weaving, and lay down thin beads. If there is a risk of the joint overheating, stop welding. Under no circumstances should cooling be accelerated by quenching or exposing the part to air flow (e.g., blowing compressed air). The cast-iron part should be fully protected from drafts. If preheating is needed, it may be applied up to a maximum of 300 °C.

Large cast-iron parts must be heated cautiously and gradually; after finishing the weld, hot sand should be poured over the area. This electrode runs smoothly and uniformly, seals the joint with adequate penetration, and produces little slag. The cast iron and weld metal fuse deeply with each other, and both materials—as well as their junction—can be filed and machined.