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An alternative process or material that exhibited excellent magnetic properties and corrosion resistance after submersion in a 5% salt solution for 1000 hours was introduced. Additional work has indicated this material can be an alternative to prealloyed ferritic stainless steels. Although prealloyed ferritic stainless steels exhibit magnetic properties comparable to wrought alloys, corrosion resistance has been less than desirable. Most prealloyed stainless steels do not sustain 100 hours in a 5% salt solution. This paper describes a mixture of elemental iron powder with 10 micron chromium powder to formulate an alloy of 430 composition upon sintering. Conditions for compacting the elemental mixture are compared with prealloyed 434L powder. Green properties, magnetic properties, and corrosion resistance related to compaction pressure, with an interpretation of results, are provided.

Often the question has been posed as to where are markets for P/M stainless steels. This question has been difficult to answer. Stainless steels are more expensive than alloy steels, because they contain chromium to provide corrosion resistance. Chromium poses a problem for P/M parts fabricators. Many sinter parts at 2050°F (1120°C). Furthermore, most insist on including at least 25% nitrogen in the sintering atmosphere. If 2050°F (1120°C) is selected for sintering, surface oxides are often only partially reduced. In addition, if nitrogen dilutes the sintering atmosphere, nitriding occurs, limiting corrosion resistance. Therefore a limited market exists for P/M stainless steels because corrosion resistance is limited. However, there is a substantial market for stainless steel bar stock. One such market, totally undeveloped, is for parts for soft magnetic applications.