Industry: Shipbuilding

Machine: Submarine

Part: Hull

Base material: Austenitic steel                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  

Description

The latest technologies for stealth and long term autonomy were utilised in the development of a new class of 60m/1’500 tonnes submarines. Among these; were the completely new designs of the hull and of the propulsion system. 

To avoid any magnetic signature, all components including the torpedoes were made of non-magnetic metals. For the hull and structure, a zero ferrite stainless steel was selected. For assembly by welding three processes were selected: submerged arc (SAW) for automated welds, semi-automatic with continuous electrodes (GMAW) and manual metal arc (SMAW). It was quickly realised that semi- automatic welding with solid wire does not give with the high quality required

Solution

The filler metals used for welding had to conform to a very strict formulation with close quality control. Exceptional weldability was needed to reduce the level of rework due to weld defects. All welds were to be X-rayed. This led to the development by the  Welding Alloys Group of a special  TUBE S metal cored wire.

The WA TUBE S filler metal was qualified for welding in all positions and for several types of joint. 

Advantages

Compared with solid wires: better weld quality, greater flexibility in setting welding parameters. Compared with manual electrodes: much higher efficiency and deposition rate, easier to master. In all cases less rework.

With the TUBE S range of metal cored wires, the  Welding Alloys Group confirms the possibility to create economically virtually any welding filler metal.  This range as well as the ranges of WA flux cored wires offers unprecedented possibilities to material engineers and designers.