Recent developments in underwater wet welding

Abstract

Developments in underwater wet welding processes over the past 25 years are reviewed. Shielded metal arc welding with rutile base coated electrodes is still by far the most common wet welding process in use. Research and development of wet welding electrodes has led to improvements in the control of hydrogen content, porosity, chemical composition, and microstructure of the weld metal. Additional work is required to develop welding consumables with improved control over diffusible hydrogen and porosity. Development of techniques such as temper bead welding has allowed successful wet welding repairs on steels having carbon equivalents greater than the traditional limit of 0.40. Alternative wet welding processes such as flux cored arc welding and friction welding are under development, but have yet to become widely accepted.

Velocidade de Propagação de Trinca por Fadiga de Soldas Subaquáticas Molhadas: Avaliação Fora da Água

“…Pode-se observar o fato relatado na literatura [1,5], onde com aumento da pressão hidrostática na soldagem subaquática molhada aumenta a quantidade de poros no metal de solda. Foram realizados ensaios de microdureza nas superfícies das seções transversais das juntas soldadas, testando metal de base, metal de solda e zona termicamente afetada pelo calor.…”

“…No entanto, tem sido reconhecido que a soldagem subaquática molhada com eletrodo revestido têm propriedades mecânicas que são geralmente inferiores às de soldagens de superfície feito em ar [1][2][3]. A norma ANSI/AWS D3.6-99 [4] especifica os testes que devem ser realizados para determinar as propriedades mecânicas para cada tipo de solda subaquática molhada.…”

Temper Bead Welding of S420G2+M Steel in Water Environment

“…Most general classification of underwater welding processes divide them into dry, wet and local dry cavity ones [1][2][3][4]. A characteristic feature of most commonly used wet welding is direct underwater contact of diver-welder, electrode and base material.…”

“…In the case of implementation of TBW technique for preventing from formation of cold cracking it is important to determine a time interval between instants of overlaying a tempered bead and tempering one. Depending on a type of applied electrode the time up to crack forming at wet welding may reach from 3 min to 2 hours [1,24,25]. Successive parameters important from the point of view of effectiveness of the process are: value of heat input in every bead as well as distance between beads axes (pitch).…”

“…Research is being conducted on the use of preheating by induction method, however, it has not found yet widespread use [20]. One of the ways to reduce the tendency to the formation of cold cracks having practical application is Temper Bead Welding (TBW) technique [1,[21][22][23][24].…”