Plasma Welding Technique

welding equipment and cutting plasma jet

Welding technique. Power arc, usually by alternating or direct current straight polarity (bypassing the electrode). Excite the arc with the oscillator. To facilitate direct excitation of the arc-duty use an arc burning between the electrode and nozzle burners .. To supply the required plasma-forming arc welding power source with an operating voltage to 120 V, and in some cases higher, to supply the plasma torch used for cutting, optimum open-circuit voltage power supply to 300 V.

The plasma jet can weld almost all metals in the lower and vertical positions, as the plasma gas using argon or helium, which can also be protective. The advantages of plasma welding are high performance, low sensitivity of the oscillations of the arc length, the elimination of tungsten inclusions in the weld metal. No bevel edges can be welded metal thickness up to 15 mm with the formation of a specific form of penetration. This is explained by the formation of through holes in the base metal, through which the plasma jet goes to the back of the product. Melted in front of the weld pool metal plasma pressure moving along the walls of the weld pool in its tail, which crystallizes to form a seam. In essence, the process is the cutting of the product from the brewing room cutting.

Plasma jet can be welded butt and fillet welds. Butt joints on metal thickness of 2 mm can be welded to the edges of the flare, with a thickness over 10 mm is recommended to bevel the edges. If necessary, use additional metal. For welding of metal up to 1 mm are successfully using microplasma welding jet indirect, in which the welding current is equal to 0.1-10 A.
Cutting plasma jet based on the melting of the metal in place of cut and blowing the plasma flow. Plasma jet used for cutting metal of thickness ranging from fractions to tens of millimeters. For cutting thin metal using a plasma jet of an indirect action. With increased thickness of the metal the best results are achieved when the plasma jet direct action. When cutting carbon steel, even in many cases it is more economical than gas-oxygen, due to the high speed and best quality of cut.

Depending on the metal as a plasma forming gas can use nitrogen, hydrogen, argon, hydrogen, argon, nitrogen, nitrogen-hydrogen mixture. Using cutting gas mixtures containing diatomic gases, more energy efficient. Dissociation, a diatomic gas absorbs a lot of heat which is released on the cold surface of the cut in the merger of free atoms in the molecule. In recent years, when it became possible to use water-cooled zirconium and hafnium electrodes, as a cutting gas and air was used. Welding and cutting can be performed manually or automatically.

See also:
Plasma Welding
Plasma Welding Introduction
Plasma Welding Technique
Microplasma Welding
Gases for plasma processing of materials
Separation of plasma jet cutting
Compression of the arc
The energy properties of the plasma arc
Rationalization of plasma welding
Plasma welding and spraying
The plasma melting and remelting
Plasmatron. Requirements for plasmatron
Plasmatron. Schemes, classification
Classification by type of electrode plasma torches
Classification of torches by the nature of the current
Structure of the plasmatron basic units