Scm Corporation

David H Ro

Erhard Klar

Charles I Whitman

C I Whitman

A process is disclosed for improving the corrosion resistance of stainless steel powders produced by atomization in an oxidizing atmosphere whereby silicon present in the powder tends to form silicon oxides on the powder surface. The process comprises adding an effective proportion of a modifier metal selected from the group consisting of antimony, arsenic, and bismuth to the melt prior to atomization. The modifier metal addition is effective for decreasing the surface silicon oxides and thereby improves the corrosion resistance.

Corrosion-resistant powder-metallurgy stainless steel powders and

The corrosion resistance of atomized tin-and-carbon containing stainless steel powders and compacts thereof is enhanced by incorporating a modifier metal into the melt prior to atomization. Effective modifier metals disclosed are niobium, titanium, tantalum, molybdenum, and the like.

Corrosion-resistant stainless steel powder and compacts made therefrom

The corrosion resistance of stainless steel powder compacts containing tin and silicon is maximized if the compacts are sintered at temperatures in excess of 2300.degree. F. in highly reductive atmospheres until the ratio of Sn:Si on the surface of the compact is at least about 1:1. Stainless steel powders atomized in an oxidizing atmosphere and containing up to about 1 percent oxygen can be utilized.

Maximizing the corrosion resistance of tin containing stainless steel

Disclosed is a process for improving the corrosion resistance of a stainless steel powder or compact thereof wherein said powder is produced by atomizing a melt of metals in an oxidizing environment whereby the resulting stainless steel powder is surface-enriched in silicon oxides. The process comprises adding an effective proportion of modifier metal to said melt prior to said atomization, said modifier metal selected from the group consisting of tin, aluminum, lead, zinc, magnesium, rare earth metals and like metals capable of enrichment about the surface of said resulting atomized stainless steel powder and effective under reductive sintering conditions in the depletion of said silicon oxides about said surface; and sintering said resulting atomized powder or a compact thereof under reducing conditions, said sintered powder or compact thereof being depleted in said silicon oxides and the corrosion resistance of said powder or compact thereof being improved thereby.

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Cleveland Heights, OH, United States of America

David H Ro