"HILDA will deliver a cost effective, low distortion welding process for EU shipyards to allow them to maintain competitiveness and produce light, strong, more fuel efficient vessels. The solid state technique will enable the modular construction of dimensionally accurate, high strength, corrosion resistant fabrications across the entire range of steels, enabling the introduction of stronger, tougher, corrosion resistant steels into the industry.HILDA will develop the fundamental metallurgical knowledge required to predict the complex phase changes and stress regimes present in welding steel. This will enable the proven, energy efficient, low hazard and environmentally benign technology of friction stir welding, widely deployed in aluminium construction for the aerospace and rail industries, to be transferred to steel shipbuilding.To achieve this breakthrough, HILDA will use real world data from friction stir welding high strength low alloy steels as an input to develop a computer model of the thermomechanical processing process at the heart of the solid state welding technique. This model will predict the phase changes, heat variations and resultant stresses associated with welding steel and generate guidelines for producing high strength welds with minimal distortion.The output from this predictive model will be used to create an expert system of easy to use software plug ins for existing FE design code that can be used by shipyards to design and manufacture vessels in accordance with Classification Society requirements. The code will be validated against a real demonstration fabrication.• HILDA will generate technical, economic, safety and environmental benefits for EU shipyards.• HILDA will advance EU computational modelling capability in the field of multi-phase simulation.• Hilda will produce weld codes useful to many other industries fabricating steel"