The welding of NM400
Welding is an important process used in the fabrication of numerous types of materials ranging from metals and alloys, to ceramics, plastics, and even fabrics. The main process itself involves the fusing of two or more materials together by melting them in localized areas. This fusion produces the final, desired joint or configuration. One such welding process that is becoming increasingly popular due to its efficiency and added value compared to other processes, is the NM400 welding technique.
The NM400 welding process is a triple pass process that utilizes two alternating electrodes, typically made of carbon or stainless steel, as well as a high-frequency current of up to 500 Amps. In the first pass, these electrodes are used to melt a narrow band around the edge of the two lap jointed substrates, effectively removing the oxide layer within the weld area. This is followed by a second pass which results in the fusing of the materials, which takes place at a much higher temperature compared to the first pass. After both of these passes are complete, the welding current is then reduced and the final pass is performed. This ‘cold’ final pass uses a low-current pass which finishes the joint by bringing it up to the desired consistency.
The advantages of the NM400 welding process over more traditional methods such as gas and arc welding can be summarized as follows:
1. Increased Resistance: The NM400 welding process generates higher temperatures than conventional welding methods. As a result, weld joints formed as a result of such a process exhibit increased resistance against wear, corrosion, fatigue and various other forms of damage.
2. Improved Lap Joint Mobility: The use of an alternating current for the welding process provides increased mobility of the lap joint due to the gradual, controlled heating that the technique utilizes. This helps avoid warping, overheating and other issues associated with abrupt, high temperatures.
3. Cost Savings: Due to the increased efficiency of the process, welders can achieve better welds in less time when compared to other welding techniques such as gas and arc welding. This leads to a considerable savings in cost, as bigger jobs can be completed faster.
The NM400 welding process is an approved solution by many leading organizations and manufacturers, and is quickly becoming the preferred welding solution due to the value that it offers in terms of reduced labor costs and improved welding results. As the technology continues to evolve and become more refined, it is likely that it will become an even more popular option for welders as time goes by.
