Friction Welding in Explosive Environmen

By 803056

Date 02-21-2006 15:07

It sounds exciting. I'ld be the one standing way over in the field, way behind everyone else.

Good luck - Al

By G.S.Crisi (****)

Date 02-21-2006 20:44

Friction welding is carried out without the need of electric arc nor flame. However, the two surfaces being welded get hot up to the point that they melt and stick together. Of course, this localized heat can produce an explosion in an explosive environment.
The National Electric Code of the USA (NEC) speaks in depth of explosive environments. Take a look also at other documents published by NFPA (National Fire Protection Association) of the USA.
Giovanni S. Crisi
Sao Paulo - Brazil

By thompsonfw Date 03-06-2006 17:10

The friction welding of a tank in an explosive environment would I think be near to impossible. I have in my experience seen the friction welding of some aerospace tank applications but before they are filled, however it would be dependant on the weld geometry. I do not know the limitations imposed by NEC but think the idea would be a non starter for the following reasons-

1) Depending on the material, the periphery of the weld area exposed to the atmosphere would reach temperatures close to that of the melting point of the parent material i.e. 400 to 650 degrees if the tank is ally.

2) The friction welding cycle in its early stages uses a higher rotational speed and lower axel thrust load to clean the faces of the pre welded pieces, before the second friction phase kicks in. This (most of the time) will produce a few sparks. These are incandescing shards of material that could be anything up to and above 4,600K.

3) I don’t know the shape of the tank but I guess it’s manufactured from some sort of plate so the weld geometry would also pose a problem.

Ether way I think it would end up in a very expensive loud boom!