ENi-CI or Nickel 99 Welding Rod (Ni-99) is a stick-welding Cast Iron rod. Ni-99 rod is mainly used for welding cast iron that requires machining.
It is also used to weld Cast iron to mild steel or carbon steel or stainless steel. Nickel 99 main content is Nickel followed by Iron. Weld deposits are silvery in color due to the high nickel amount.
The weld made using ENi-CI or Nickel 99 rods is soft but lacks ductility- only 3 to 6% elongation.
Note: Nickel 99 is ENi-CI and Nickel 55 is ENiFe-CI classification rods.
ENi-CI: Nickel 99 Rod Specification
The specification for ENi-CI or Nickel 99 Rod (Ni-99) is AWS A5.15. The meaning of ENiCI is:
- ”E” means Electrode,
- ”Ni” means Nickel,
- ”CI” means cast iron.
Nickel 99 Rod Chemical Composition
Chemical compositions of Nickel 99 (Ni-99) or ENi-CI welding rods are given in the below table. The main alloying element is nickel which has to be a minimum of 85%.
| Element | Weight % |
|---|---|
| Carbon | 2.0 maximum |
| Manganese | 2.5 maximum |
| Silicon | 4.0 maximum |
| Sulfur | 0.03 maximum |
| Iron | 8.0 maximum |
| Nickel | 85.0 minimum |
| Copper | 2.5 maximum |
| Aluminum | 1.0 maximum |
| Other elements | 1.0 maximum |
Nickel 99 Rod Mechanical Properties
The tensile strength of Nickel 99 (ENi-CI) welding rod is 40- 65 Ksi or 276- 448 MPa. The weld deposit hardness is around 135- 218 BHN.
The below table gives the mechanical properties of the Nickel 99 rod as required by AWS A5.15 specification.
| Property | Value |
|---|---|
| Tensile Strength, Ksi (MPa) | 40- 65 (276- 448) |
| Yield Strength, Ksi (MPa) | 35- 60 (262- 414) |
| % Elongation | 3- 6 |
| Hardness (BHN) | 135- 218 |
| Toughness (Joules) | Not specified |
Nickel 99 Rod Setting
Nickel 99 rod can be used with AC and DC welders. DC welders using Reverse polarity are used for welding using Ni-99 rods.
Recommended Nickel 99-rod settings are given in the below table for reference. For actual use, try or scrap metal before use.
Nickel 99 Rod Polarity
Nickel 99 or ENi-CI welding rods can be used with AC and DCEP Polarity. The welding arc is smooth and easy to ignition.
To learn about Types of Welding Polarity and how it works, read my this article on Welding Polarity.
The slag is easily removable and welds are usually crack-resistant. Welding using DCEN polarity is not recommended due to unstable arc characteristics.
Nickel 99 MIG Welding Wire
Nickel 99 Welding rod is available in wire spool form. The wire classification is as per AWS A 5.15 specification.
Check out the below best Nickel 99 MIG welding wires for use.
Nickel 99 vs Nickel 55
Both Nickel 99 and Nickel 55 are cast iron welding rods. The main differences are:
- Nickel 55 contains 45-60% Nickel while Nickel 99 contains a minimum of 85% Nickel.
- Nickel-55 weld has higher hardness and tensile strength compared to Nickel 99.
- Nickel 99 has low ductility while Nickel 55 welds are more ductile.
- Nickel 99 weld has good machinability.
- The hardness of the ENi-CI weld deposit is around 210 Brinell (HB) which is quite low compared to ENiFe-CI which gives a weld deposit hardness of 350 HB.
Read my article to know about the Nickel 55 (ENiFe-CI) welding rod in detail, one of my favorite rods for welding cast iron.
Nickel 99 welding rod uses
Nickel 99 rods give a softer weld deposit compared to other cast iron welding rods.
This rod is used for welding gray cast irons to weld cast iron to steel or casting repairs in foundries.
Nickel 99 weld deposits have low weld strength and ductility that gives excellent machinability after welding.
ENi-CI can also be used for welding ductile cast irons and malleable cast irons but remember, the weld strength is low with this rod compared to Nickel 55 rod.
Nickel 99 welding tips
When welding difficult cast irons apply peening on welds. Simply, after u finish a weld pass, use a chisel hammer for pinning by hitting it from the pin head side.
Use cold welding technique. Cast irons that are prone to cracking should be avoided to preheat. Apply preheat only in case of oily castings.
Avoid the use of high welding amperage. This will reduce the weld dilution from cast iron and hence provide a better weld deposit.
Nickel 99 or Nickel 55 welding rods do not require any baking. Simply you can open the packet and proceed with welding.
