Corrosion Resistance of High Strength P/M Austenite Type Stainless Steels

Corrosion resistance of high strength P/M austenite type stainless steels (SUS 304L) obtained by the addition of boron or P was investigated. Corrosion tests by JIS method were carried out by intergranular and general corrosion tests, and the corrosion resistance was compared with P/M stainless steels (three types) and wrought stainless steel. As a result, in the intergranular corrosion test using 65% boiling HNO sub 3 solution, a B 0.2 wt.% added P/M stainless steel shows good corrosion resistance and the corrosion loss values are equivalent to wrought stainless steel. Phosphorus 0.2 wt.% added P/M stainless steel shows poor corrosion resistance because of localized corrosion of phosphide that precipitated along grain boundaries. On the other hand, in the general corrosion test using 5% boiling H sub 2 SO sub 4 solution, the behavior of corrosion is closely related to the density of specimens.