Underwater Wet Welding with Ni, Fe-Ni, and Stainless Steel Electrodes

Abstract

In the case of underwater wet welding, weld crack often occures in heat affected zone.
The purpose of the study was to decrease or prevent this crack by using Ni, Fe-Ni and stainless steel electrodes.
SS41 steel plate of 12 mm thickness, SM50C steel plate of 12 mm thickness and 80 kg/mm² grade high strength steel plate (WT80C) of 16 mm thickness were used as base metals.
The results were summarized as follows,
(1) Using Ni, Fe-Ni, D309 and D310 electrode in welding SM50C and WT80C were effective to prevent under bead crack and crack free weld was able to be obtained. Furthermore there were not found any craking in weld metals of SS41, SM50C and WT80C steel.
(2) There were found underbead crack and weld metal crack in welded parts of SS41, SM50C and WT80C steel with D430 electrode.
(3) The microscopic segregation of Ni and Cr in weld metals of SS41, SM50C and WT80C steel with austenitic stainless steel electrodes were a little.