Corrosion Products Development on Haynes282 Gamma - Prime (γ') Strengthened Alloy at 550 °C Under Salt Mist Conditions for 500 Hours

Prior to utilizing new advanced materials in coal power plants, a large number of experimental testing is required. Test procedures are needed in specialized high temperature laboratories with state of the art facilities and precise, accurate analytical equipment capable of performing tests at a variety of temperatures and environments. In this study, the results of a unique technique involving salt spray testing at high temperatures are presented. The Haynes 282 gamma – prime (γ’) strengthened alloy fabricated by means of three different manufacturing processes: HAYNES 282 WROUGHT alloy, Haynes 282-SINT alloy, and finally Haynes 282-CAST alloy have been tested. The materials have been exposed to a salt spray corrosion atmosphere using 1% NaCl - 1% Na₂SO₄. Post exposure investigations have included SEM, EDS and XRD examinations. The test using salt spray of 1% NaCl - 1% Na₂SO₄ water solution at 550 °C for 500 hours indicted no influence on the corrosion products formation, where Cr₂O₃ has been developed in all three alloys, whereas NiO has been found only in Haynes 282-CAST material. On the other hand, it has been found that the fabrication process of HAYNES 282 alloy strongly influences the corrosion products formation under the high temperature exposures.