POST WELD HEAT TREATMENT FOR CHEMICALLY STABILIZED AUSTENITIC STAINLESS STEEL

摘要

Thermo-mechanicl properties of welds in stainless steel is substantially improved by the implementation of a post weld heat treatment that iliminates sigma phase in the heat treated zone and favors niobium carbonitride precipitate formation in a desirerable size range. In most cases, post weld heat treated material can be employed in pressurized devices at temperatures exceeding 550~C, which is curently regarded the upper safe temperature limit , and material according to the inventive subject matter was tested at temperature of up to 850~C without reheat cracking.