Method of welding for exfoliation prevention of stainless steel weld-overlay

摘要

A welding method for stainless steel overlays is disclosed wherein a welded stainless steel overlay is prevented from exfoliating out of an inner surface of a high pressure vessel. Hydrogen exists at a partial pressure of less than 150 kg/cm2 and a temperature less then 450 DEG C. in the pressure vessel. At least one low alloy steel weld-overlay is preliminarily welded over the inner surface of the pressure vessel. The preliminarily low alloy steel weld-overlay is composed of similar composition to the base metal of the vessel, containing niobium and/or nickel. Thereafter, at least one customary ferritic steel or austenitic steel weld-overlay is welded thereon.