B444M2 FERRITIC STAINLESS STEEL WITH IMPROVED HIGH-TEMPERATURE OXIDATION RESISTANCE AND PREPARATION METHOD THEREFOR

摘要

The present invention relates to the technical field of metallurgical materials, and specifically relates to a B444M2 ferritic stainless steel with improved high-temperature oxidation resistance, and a preparation method therefor. The chemical components of the ferritic stainless steel comprise the following (in weight percentage): C 0-0.01%; Si 0.4-0.6%; Mn 0.25-0.35%; S 0-0.009%; P 0-0.01%; Cr 19-20%; Nb 0.4-0.5%; Ti 0.1-0.2%; N 0-0.01%; Mo 1.9-2.1%; W 0.4-0.6%; and Ce 0.04~0.1%; the remainder is Fe. The micro-structure of the ferritic stainless steel is ferrite, and precipitates of a size of 200-400 nm are dispersed in the grain boundaries and in the crystals. Smelting molten steel according to the set composition, casting into a casting blank, and forging after high-temperature homogenisation treatment; re-heating the casting blanks to 1200℃ ±15℃ and maintaining the temperature and, after rolling 6-8 times, acquiring hot-rolled sheet; annealing the hot-rolled sheet and removing the surface iron oxide scale, and then implementing cold rolling to acquire cold-rolled sheet; and keeping the cold-rolled plate at 1020℃ ±15℃ for 1.5-2.5 min for annealing. Thus, a ferritic stainless steel material with excellent high-temperature oxidation resistance and good formability is obtained.