Can you weld Ni-Hard?
Martensitic cast iron (Ni-Hard types) and the various white irons are generally considered too crack-sensitive or brittle to be welded satisfactorily.
What is Ni-Hard casting?
Ni-Hard is the generic name for a family of white cast irons alloyed with nickel and chromium to give high hardness and outstanding resistance to abrasion.
Which cast iron Cannot be welding?
White cast iron which is very hard and contains iron carbides, is normally considered to be unweldable.
Can you weld white cast iron?
All categories of cast iron except white iron are considered as weldable, although the welding can be significantly more difficult compared with carbon steel welding.
Where is Ni hard iron used?
Ni-Hard castings are typically used in power generation, brick, asphalt, cement, concrete, rock, sand and gravel industries. Typical castings are mill or mixer liners, mixer tips and slurry pumps.
What is the effect of nickel on cast irons?
Nickel is one of the most common alloying elements because it refines the pearlite and graphite structure, improves toughness, and evens out hardness differences between section thicknesses.
What is NI resist material?
Ni-Resist or Ni Resist alloy grades are austenitic gray cast iron casting grades that provide good hardness, dampening, and some corrosion resistance. These grades are very brittle and cannot be welded.
Why are cast irons considered difficult to weld successfully?
It melts fairly easily, so why is it so hard to weld? Welding cast iron is difficult because it has a high carbon content (about 10x that of most steels), and it’s brittle and prone to cracking. Thermal stresses are challenging to remove from the Heat Affected Zone, and cracks will likely propagate over time.
Is malleable cast iron weldable?
The chemical composition of malleable cast iron is much the same as that of a typical gray iron, but its properties are much different. It is tough; it can resist shock; it has ductility approaching that of mild steel. However, malleable iron castings can usually be braze welded successfully.
Is cast iron hard to weld?
Cast iron is difficult, but not impossible, to weld. In most cases, welding on cast iron involves repairs to castings, not joining casting to other members. The repairs may be made in the foundry where the castings are produced, or may be made to repair casting defects that are discovered after the part is machined.
Can you weld cast iron with a TIG welder?
Cast iron can definitely be welded, and it can also be brazed – including with TIG brazing. ‘TIG brazing, with a TIG welding machine, may offer a satisfactory alternative to other processes. With TIG brazing you use lower amperage to heat the workpiece, but without actually melting the cast iron.
Is it possible to weld a cast iron cast?
Cast iron is difficult, but not impossible, to weld. In most cases, welding on cast iron involves repairs to castings, not joining casting to other members.
Do you need nickel electrode when welding cast iron?
When at this temperature, conditions that can lead to cracking occur. While the arc will heat the casting to temperatures above this level, it is important that the casting not be held at this temperature for long periods of time. If the part is to be machined after welding, a nickel-type electrode will be required.
What should the temperature be when welding cast iron?
Remembering this is helpful when welding cast iron: during and after welding, the casting must either be allowed to cool slowly, or should be kept cool enough that the rate of cooling is not important. A critical temperature in most cast iron is about 1450 degrees F.
What makes up the microstructure of Ni hard?
Ni-Hard has a microstructure consisting of carbides and a martensitic- austenitic-bainitic or predominantly martensitic matrix. This is achieved by a balanced composition of carbon, nickel, chromium, silicon, and final heat treatment. Machining the Ni-Hard 1 casing of a slurry pump