Nickel Welding Characteristics and Techniques
Dynamic Fabrication is your total source for nickel welding, fabrication, machining, and assembly. We produce high quality work ranging from precision parts to complete assemblies. Nickel undergoes no phase changes as it cools from melting point to room temperature like stainless steel. Nickel alloys cannot be hardened by quenching. Nickel and its alloys are used in high temperature oxidation, creep resistance, and aggressive corrosive environments. It is also used low temperature cryogenic applications. DFI is certified in nickel welding. We guarantee superior workmanship and quick turn-around. Founded in 1981, Dynamic Fabrication serves a wide variety of industries.
High-quality welds can be produced in nickel alloys by conventional welding processes. Some of the characteristics of nickel alloys require using different techniques than carbon and stainless steels. Nickel alloys can be welded by all welding processes, except forge welding and oxyacetylene welding. Here is a link to a Nickel Welding video.
The choice of welding process is dependent on many factors such as metal thickness, component design, joint design, if the weld will be exposed to a corrosive environments, and any special field conditions.
When MIG welding nickel alloys, it is similar to welding carbon steels. Nickel has similar mechanical properties to carbon steel. Its the nickel crystalline structure is different from iron. In contrast to carbon steels, when welding nickel, the nickel does not undergo a crystalline change up to its melt temperature. Change the grain structure requires cold working and annealing. Nickel has great solubility. Small amounts carbon, manganese, silicon, and aluminum are often added. Some of these have a positive influence on the weld and some have a negative influence. For example Manganese in the range of 3 to 9 percent is added to nickel copper alloys to improve crack resistance. Titanium is sometimes added to the filler metals as a deoxidizer for weld porosity reduction.
Another characteristic of Nickel welding is lower weld penetration. This is caused by the properties of nickel and must be considered by the welder. A lower penetration makes it necessary to use smaller lands in the root of the joint. Increasing weld current will not increase the penetration of the arc. Excessive weld current can cause overheating of covered electrodes. Excessive weld heat with gas shielded processes results in weld spatter and overheating of the welding equipment. Welding Nickel requires proper joint design.
The most widely employed processes for welding nickel alloys are gas-tungsten arc welding, gas-metal arc welding, and shielded metal arc welding. Typically straight argon is the gas of choice, and when more weld energy is required argon with 40% helium have been use for MIG and pulsed MIG.