摘要 |
<p>By including nitric acid and hydroxylamine in a manganese phosphating composition and controlling the ratio of nitric to phosphoric acids and the ratio of Total Acid to Free Acid within a specified range, satisfactory manganese phosphate conversion coatings can be obtained within a reasonable time at temperatures much lower than has previously been thought necessary for operating a manganese phosphating composition with no other metal cations (except possibly for iron).</p> |