| Abstract Scope |
Dynamic Solid State (DSS) uses all of today's technology but arranged in a slightly different order. It used induction heating that supplies over 95% of the energy required to bond, Forge and Shear makes up the remaining 5% (EWI evaluation 2012)
The procedure is to place an induction coil in-between work pieces, take to hot working temperature below melting in an inert environment, remove coil, push / forge and rotate / shear. Result is a weld that has no heat affected zone, fine grained base to base, no fusion line, hardness mapping similar to base metal (slightly harder at fusion zone) but no softness. And OD, ID in compression, across weld in tension. Thus 12, 3, 6 and 9 o'clock, residual stress distribution are identical. Resist embrittlement.
To date this technique has joined steel, stainless, titanium, zirconium and dissimilar materials. Why does this deserve consideration? Because it can unify global welding standard into one.
Right now each country / region has individual welding standards, slightly different but enough such that welder from one region has to be certified for another region. AWS, ASME, Lloyds, DNV, IIW, CWB etc. Each welder has their own particular interpretation, habit. Welding sticks, inspection criteria are not uniform.
DSS offers uniformity, standardization, modular procedure anywhere in the world under all weather conditions. Will it replace manual welding? No. DSS is suitable for identical, repeatable geometries. For low cost, one off welds, manual is still supreme. Technique joins using technicians. Not welders.
For nuclear power plants, submarine or hydrogen pipeline DSS can offer significant advantages because quality, repeatability and speed is pre-determined. The combination of certainty of quality will enable complex projects to be built w/ more predictability. |