The effect of Ce-implantation on the corrosion of alloy 800H in a sulphidizing/oxidizing/carburizing environment at 700 C
In several commercial high temperature processes, for example coal gasification, structural materials are exposed to atmospheres of low oxygen potential with medium to high sulphur partial pressures. Sulphidation attack can be a significant problem, but the addition of small amounts of reactive elements is known to improve the protective qualities of the oxides which are formed simultaneously. In this paper, the effect of cerium ion implantation on the corrosion behaviour of Alloy 800H in a simulated coal gasification atmosphere is reported. These investigations have shown that the attack of Alloy 800H in a S-O-C gaseous atmosphere can be reduced by implantation with a high dose of Ce. In both unimplanted and implanted material, sulphides and oxides were formed, but the corrosion products of the implanted material showed a higher Cr:Fe ratio. It is suggested that this feature may be responsible for the observed improvement in corrosion resistance. The reason for this higher Cr:Fe ratio is not fully understood. It is possible that several interrelated factors play a role, e.g. changes in relative diffusion rates of Cr and Fe and/or a reduction of S-activity at the surface during the initial stages of corrosion.
Bibliographic Reference: Paper presented: Gordon Research Conference on Corrosion, Colby-Sawyer College, New London, New Hampshire (US), July 17-21, 1989
Availability: Available from (1) as Paper EN 34972 ORA
Record Number: 198911149 / Last updated on: 1994-12-01
Original language: en
Available languages: en