Study on Welding of High Strength Steel with High Toughness for Pressure Hull of Deep Submergence Vehicle (Report 2)

Abstract

For pressure hulls of Deep Submergence Vehicle (DSV) operating in seas of 2000 m depth, the most important point is the maximum load carrying capacity under the minimum weight. For this reason, spherical shell made of high strength steel is adopted for pressure hulls.
The authors investigated heat treatment conditions and GTAW welding conditions of HT 100 steel (5Ni-Cr-Mo-V QT steel with a yield strength of 90 kgf/mm²) in report. 1.
In this report, a procedure of decision of welding conditions for high strength steel like HT 100 is proposed. And using this procedure the full scale model of spherical pressure hull was fabricated. After completion of this model, the weld metal was proved to satisfy the requirements of the destructive and non-destructive tests.