New Technologies / Research & Development

New Plasma Welding Technology

New Plasma Welding Technology
Butt welding with no edge preparation necessary
Welding with one pass for plate thiknesses up to 15mm
Smaller heat input range generates less welding stress than conventional methods
Less occurrence of weld defects

Background and History of

【Market for technology development】

・Due to the corrosionresistant and lightweight benefits of aluminum and aluminum allys, there is a large market for them in logistics equipment (ships, rail), industrial plants ( electric power and chemical plants) and other various structural equipment.

【Some Challenges】

・When welding aluminum merals, the plates to be joined must be cut in a V-shape, or an X-shape (edge preparation).
・For thichen plates, the number of runs and thermal detormation increase to create problems both economically as well as in the product quality.

【Technological Challenges】

・While a welding technique that would eliminate the need for edge preparation would have been the required solution to the abovementioned issues, because methods like electron beam welding and laser welding involved highly expensive facilities, the issue of high-precision preparation became a large barrier in the use of the aforementioned technique.
・Plasma welding, on the other hand, required relatively cheap equipment, was highly versatile and was considered to have the highest prospects. however, due to hte current limiting on conventional plasma welders, welding was limited to plates under 5mm thick.

General Outline and Results of Research & Development

【General Outline of the New Plasma Welding Technology】

・In 2007, our company was approved for the Ministry of Economy, Trade and Industry's Senryakuteki kiban gijutsu kodoka jigyo (Project for Advancing Core Strategic Technologies), begining our development of plasma welding technology. Later, in 2011, we were authorized for the shin renkei keikaku(new collaboration plan), starting our engagement in the practice of a "new plasma welding technology" suited for medium to highly thick plates, through a colaboration between industry, academia and government.
・More specifically, this entailed:
  a. Concentration of energy densities, optimization of simulations
  b. Optimization of torch shape
  c. Enhancement of welding system and construction techniques


・Developed a welding and construction system involving a welding robot able to weld plates up to 15mm in one pass.
・Confirmed that the new plasma technology provides greater quality as compared to conventional methods.

Specifications of Developed Products / Technologies

・Welding procedures involving this welding technology have been gualitied by the high Pressure Gas Safety Institute of Japan (Ministry of Economy, Trade and Industry) and the Japan Boiler Association (Ministry of Health, Labor and Welfare).

Performance Comparison with Conventional Welding Methods
TIG/MIGLaser weldingElectron beam weldingConventional plasma weldingNew plasma welding
Weldable Thikness in 1 pass(AL/mm) 〜5 〜4 over 100 〜5 6〜15
Edge shape V/X | | | |
Edge precision(mm) 〜1.0 〜0.2 〜0.5 〜1.0 〜1.5
safety / Environmental load Atmospheric Atmospheric radiation Vacuum radiation Atmospheric Atmospheric
Dimensional limits None None Yes None None