Element Six has developed a material believed capable of withstanding the high
temperature, high reactivity, high force, and severely abrasive environment that characterise
the friction stir welding (FSW) of steel. A second series of tools were generated, based upon that
initial work, but now designed for welding steel from 8 to 12mm thick. The physical delivery of
this series of 12mm tools to TWI for testing represented the fulfilment of deliverable D1.2 of
project RESURGAM, stated as: D1.2 Baseline puck and tools for welding steel from 8 to 12 mm
From this point the work continued in this task to achieve the D1.3: Preliminary Friction Stir
Welding machine specification for carbon steels in air, developed by TWI. This report
preliminary FSW machine specification for two friction stir welding machines:
- One capable of performing an underwater patch repair in steel up to 12mm thick, this machine
being developed under the leadership of Forth Engineering in Work Package 3;
- A second FSW system capable of being retrofitted to an existing CNC machine to perform FSW
in air for the manufacture of ship sub assemblies such as stiffened panels.This FSW system is
being developed under the leadership of Stirweld in WP4.
The report outlines the basic principles of friction stir welding and the particular
considerations that need to be made when the process, originally developed for aluminium, is
transferred to welding steel. These specifications are based upon the early stage output from Work
Package 1, and before the welding process parameters have been optimised, either for maximising
the welds’ properties or for minimising the requirements placed on the FSW machine.
Also during this first 12 months the work to achieve the D 1.4 ( Report on baseline tool
reliability, repeatability and longevity) started.