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J. Łabanowski, D. Fydrych and G. Rogalski

Underwater Welding - A Review

The paper describes principles of underwater welding and recent trends in research works undertaken for enhance welding technology and properties of underwater welds. Department of Materials Technology and Welding at Gdansk University of Technology (GUT) has been involved in underwater welding research for over 25 years. Investigations include technology of underwater welding, and weld properties examinations. All tests have been performed with the use of self designed stands allow to perform welds in shallow depths as well as the depths up to 1000 m. The main investigation directions performed at the Department of Materials Technology and Welding are presented:

Weldability of HSLA steel and factors influencing susceptibility to cold cracking of welded joints.

The effects of wet welding conditions on diffusible hydrogen amount in the welds.

The effects of heat input, underwater welding depths and composition of shielded gases on welds toughness.

Open access

D. Fydrych, J. Łabanowski, J. Tomków and G. Rogalski

Abstract

Water as the welding environment determines some essential problems influencing steel weldability. Underwater welding of high strength steel joints causes increase susceptibility to cold cracking, which is an effect of much faster heat transfer from the weld area and presence of diffusible hydrogen causing increased metal fragility. The paper evaluates the susceptibility to cold cracking of the high strength S355G10+N steel used, among others, for ocean engineering and hydrotechnical structures, which require underwater welding. It has been found from the CTS test results that the investigated steel is susceptible to cold cracking in the wet welding process.

Open access

J. Łabanowski, K. Prokop-Strzelczyńska, G. Rogalski and D. Fydrych

Abstract

The present work was conducted to assess the weldability of duplex stainless steel in underwater conditions. Metal manual arc welding (MMA) with the use of coated electrodes was used in the investigations. Tekken weldability tests were performed underwater at 0.5 m depth and in the air. Nondestructive tests, metallographic examinations of welds, ferrite content assessment in microstructure and hardness test were performed. The good weldability at underwater conditions of duplex stainless with the use of MMA method was confirmed, however difficulties in stable arc burning were revealed.

Open access

D. Fydrych, A. Świerczyńska, G. Rogalski and J. Łabanowski

Abstract

The article presents the idea of the use of Temper Bead Welding (TBW) technique to improve the weldability of high strength steel at underwater wet welding conditions. Wet welding method with the use of covered electrodes is described. This work shows results of metallographic examinations and hardness measurements of samples of S420G2+M steel with weld beads performed under water. It has been shown that Temper Bead Welding technique may provide a way to reduce the hardness of the welds, thus is a useful method for improving weldability of high strength steel welded in underwater conditions. The optimum overlap of weld beads (pitch) was set of 55÷100%.

Open access

D. Fydrych, J. Łabanowski, G. Rogalski, J. Haras, J. Tomków, A. Świerczyńska, P. Jakóbczak and Ł. Kostro

Abstract

Wet welding with the use of covered electrodes is one of the methods of underwater welding. This method is the oldest, the most economic and the most versatile. The main difficulties during underwater wet welding are: high cooling rates of the joint, the presence of hydrogen in the arc area and formation of hard martensitic structure in the weld. These phenomena are often accompanied by porosity of welds and large number of spatters, which are more advanced with the increase of water depth. In this paper result of non-destructive tests, hardness tests and metallographic observations of S500MC steel joints performed underwater are presented. The weldability of 500MC steel at water environment was determined