Friction welding of fittings and nozzles from low-alloy steel 15Х2НМFА

ABSTRACT

The purpose of this work is research and development of technology of friction welding instead of manual arc welding with coated electrode, fittings and pipes shell-type equipment of power plants of steel 15X2NMFA. Manual arc welding method does not provide a stable quality of welded joints. The solution to this problem is possible through the use of friction welding process fittings and pipes of small diameter. Given the lack of theoretical and experimental exploration of issues were raised and resolved the following scientific and technical tasks: developed by making constructive models and connected (cone) surfaces of the fittings (diameter up to 40 mm) and pipes (diameter up to 80 mm); choice of optimum training grounded corners conical surfaces to be welded; justified the choice of optimum welding parameters values; quality assessment of welded joints by non-destructive and destructive methods. Effect of constructive and technological factors on the quality of welded joints. Received the positive results of the pilot study confirmed the technological feasibility of friction welding fittings and pipes of small diameter low-alloy steel 15X2NMFA.

KEYWORDS:

• Friction welding
• low alloy steel
• construction cutting
• model choke
• model fitting pipe
• welding parameters
• the hardness of the weld
• macrostructure
• microstructure
• weld quality