Huge size and corrosive environment are two key aspects, which shall be considered in building of ships and offshore structures.
Both gas and plasma arc cutting processes may be used in manufacturing depending on the material and requirements set for produced items. Reliable joints may be obtained using arc welding processes (MIG-MAG, TIG, plasma arc welding) or gas welding, which are selected based on actual conditions and the type of welded material. Though this industry generally uses heavy structures, laser welding has recently been introduced into shipbuilding, for example for welding of multi-layer sandwich panels.
40-50% of time during ship hull manufacturing is spent on strain relief. Flame gouging is a preferred method for strain relief. This process is recommended for local welding defects removal before re-welding. On the other hand flame cleaning process is designed only for heat treatment of large surface areas and it is used for removal of rust, paint, grease etc.
Parts and assemblies are often protected against wear and corrosion by special coatings, which are applied or built up on the surface. This may be achieved by both welding processes and thermal spraying. Such method of part refurbishment is much cheaper and faster, than complete replacement or manufacturing of a new piece. Moreover, coating may be applied locally.
A particular thing about this industry is that it uses a large number of vertical welds and welded parts are usually very thick, which often requires several runs. All structures manufactured by this industry are regulated by relevant registers. Strict requirements are applied to welds and thus high quality of used materials, including industrial gases and mixtures shall be applied and regulations (GOST, OST, TU) shall be available