Corrosion resistant powder metal parts

Abstract

Abstract A METHOD OF PROVIDING A POWDER METAL ARTICLE SUBJECTED TO A CORROSIVE HALOGEN ION CONTAINING ENVIRONMENT WITH CORROSION RESISTANCE THERETO, WHICH COMPRISES THE STEPS OF: PRESSING METAL POWDER INTO A GREEN COMPACT; SINTERING THE GREEN COMPACT IN A SUBSTANTIALLY NON-OXIDIZING ATMOSPHERE, THEREBY FORMING A SINSTERED ARTICLE; SUBSTANTIALLY IMPREGNATING AND COATING THE SINSTERED ARTICLE WITH AN AQUEOUS ALKALI METAL SILICATE SOLUTION; CURING THE SOLUTION AT A TEMPERATURE OF AT LEAST ABOUT 300*F. TO DRIVE OFF THE WATER RADICAL OF THE SOLUTION, AND RENDER THE ARTICLE POROUS AAND THE SILICATE IMPREGNAT AND COATING WATER INSOLUBLE; AND PLACING THE ARTICLE INTO SERVICE IN A CORROSIVE HALOGEN ION CONTAINING ENVIRONMENT. A PRESSED AND SINSTERED POROUS POWDER METAL ARTICLE COATED BOTH EXTERNALLY AND INTERNALLY ALONG POROUS PASSAGES WITH A CURED ALKALI SILICATE COATING HAVING AN AVERAGE THICKNESS OF AT LEAST 15 MICROINCHES AND WHICH IS CAPABLE OF WITHSTANDING A 5% AQUEOUS SODIUM CHLORIDE SPRAY SOLUTION, WITHOUT SHOWING SIGNS OF RUSTING, PITTING OR STANING AT NORMAL VISUAL LEVELS, FOR A PERIOD IN EXCESS OF 100 HOURS, IN ACCORDANCE WITH TESTING PROCEDURES ESTABLISHED BY ASTM DESIGNATION B117-64.

Inventors

• 👤 J Conner
• 👤 O Reen
• 👤 L Burrell

Bibliographic Details