TY - JOUR

T1 - Induction Heating in Underwater Wet Welding—Thermal Input, Microstructure and Diffusible Hydrogen Content

AU - Brätz, Oliver

AU - Klett, Jan

AU - Wolf, Thomas

AU - Henkel, Knuth Michael

AU - Hassel, Thomas

AU - Maier, Hans Jürgen

N1 - Funding Information: Funding: The publication of this article was supported by the TIB Open Access Fund of the Leibniz Universität Hannover and Technische Informationsbibliothek (TIB). Acknowledgments: This study was a part of the DVS research project IGF 20.199 B funded by the AiF as a part of the program to support “Industrial Community Research and Development” (IGF) funded by the Federal Ministry for Economic Affairs and Energy on the basis of a decision of the German Bundestag.

PY - 2022/2

Y1 - 2022/2

N2 - Hydrogen-assisted cracking is a major challenge in underwater wet welding of high-strength steels with a carbon equivalent larger than 0.4 wt%. In dry welding processes, post-weld heat treatment can reduce the hardness in the heat-affected zone while simultaneously lowering the diffusible hydrogen concentration in the weldment. However, common heat treatments known from atmospheric welding under dry conditions are non-applicable in the wet environment. Induction heating could make a difference since the heat is generated directly in the workpiece. In the present study, the thermal input by using a commercial induction heating system under water was characterized first. Then, the effect of an additional induction heating was examined with respect to the resulting microstructure of weldments on structural steels with different strength and composi-tion. Moreover, the diffusible hydrogen content in weld metal was analyzed by the carrier gas hot extraction method. Post-weld induction heating could reduce the diffusible hydrogen content by −34% in 30 m simulated water depth.

AB - Hydrogen-assisted cracking is a major challenge in underwater wet welding of high-strength steels with a carbon equivalent larger than 0.4 wt%. In dry welding processes, post-weld heat treatment can reduce the hardness in the heat-affected zone while simultaneously lowering the diffusible hydrogen concentration in the weldment. However, common heat treatments known from atmospheric welding under dry conditions are non-applicable in the wet environment. Induction heating could make a difference since the heat is generated directly in the workpiece. In the present study, the thermal input by using a commercial induction heating system under water was characterized first. Then, the effect of an additional induction heating was examined with respect to the resulting microstructure of weldments on structural steels with different strength and composi-tion. Moreover, the diffusible hydrogen content in weld metal was analyzed by the carrier gas hot extraction method. Post-weld induction heating could reduce the diffusible hydrogen content by −34% in 30 m simulated water depth.

KW - Fine-grained construction steel

KW - Hydrogen analysis

KW - Hyperbaric wet welding

KW - Induction heating

KW - Post-weld heat treatment

KW - Preheating

KW - Underwater technology

UR - http://www.scopus.com/inward/record.url?scp=85124895535&partnerID=8YFLogxK

U2 - 10.3390/ma15041417

DO - 10.3390/ma15041417

M3 - Article

AN - SCOPUS:85124895535

VL - 15

JO - MATERIALS

JF - MATERIALS

SN - 1996-1944

IS - 4

M1 - 1417

ER -