Improvement in Mechanical Properties and Corrosion Resistance of Powder Metallurgy Type 430L Stainless Steel Sintered in Nitrogen-Hydrogen Atmosphere

Abstract

Powder metallurgy (PM) AlSI 430L (UNS S43000) sintered in a nitrogen-hydrogen atmosphere was investigated to obtain an acceptable balance of mechanical properties and corrosion resistance. High-temperature solution annealing (1.150 degrees C, 60 min) and some post-sintered aging heat treatments 0 00, 200, 300. 375, 675, and 850 degrees C) for different times (90 min, 4.6, 8. and 48 h) were performed. The effects of nitrogen and temperature/time aging on localized Corrosion were analyzed by using an exposure method (ferric chloride test. ASTM G48) and anodic polarization measurements (ASTM G5). Experimental results showed that high-temperature solution annealing provides even better corrosion resistance than the material sintered in vacuum. Also, aging at low temperatures shows a positive effect on mechanical reinforcement without losing significant levels of corrosion resistance.