Electrochemical reactivation methods applied to PM austenitic stainless steels sintered in nitrogen–hydrogen atmosphere

Effect of ageing heat treatments on the microstructure and intergranular corrosion of powder metallurgy duplex stainless steels

“…The 675°C temperature was the typical critical sensitization temperature for austenitic stainless steels [28]. For 316L N also high DOS was registered with a clear increase of EPR data with sensitization time but it was noticed that the precipitation and subsequent sensitization occurred faster when the sensitization temperature was increased up to 875°C, differing with what is expected for wrought stainless steels.…”

“…Previous works [14,28,29] indicate that Q r parameter is recommended to be used instead of I r since the former is an integration value while the latter is just a point value. Additionally, due to the porosity, the real current density cannot be correctly estimated.…”

“…For the case of base materials sintered in nitrogen, sensitization at the critical 675°C temperature showed for 316L N samples [28] slight TG carbide precipitation. With increasing heat treatment time, a progressive intergranular etching was detected showing ditch structure type for the longer heat treatments.…”

“…The positive effect of Cr, Mo and N on PREN number (Pitting Resistance Equivalent Number) is known but only if they are in solid solution and homogeneously distributed [23,24]. If precipitated, nitrogen plays a negative role [10,21,[24][25][26][27][28][29].…”

Effects of Debinding and Sintering Atmosphere on Properties and Corrosion Resistance of Powder Injection Molded 316 L - Stainless Steel

“…A previous study of immersed PIM 316L SS parts in 3% NaCl solution for 78 days and found that 316L SS displayed pitting corrosion because of pores present in 316L SS (Sobral et al 2001). Another study investigated the effects of sintering atmosphere on pitting corrosion resistance of 316L SS produced by powder metallurgy (PM); the authors found that vacuum sintering helped to attain high density and better corrosion resistance compared with gas sintering (García et al 2008(García et al , 2007. In gas-sintered samples, lamellar components form.…”