Corrosion performance of high-chromium weldments in simulated medium-Btu coal gasifier atmospheres.

摘要

Metallic components in coal gasification systems are exposed to severe corrosive environments containing oxygen and sulfur. Metallurgical coating is an economical and practical solution to material degradation problems created by such environments. Various studies indicate that chromized coatings provide the best protection against corrosion. However, in practical systems, weldments are used for joining and field repair of coated components, and the compatibility of the filler materials in the weldment with the hostile gaseous environments becomes the critical issue in overall corrosion performance in coal gasifier atmospheres. In this study, several commercial high-chromium filler materials containing various amounts of nickel were evaluated in a simulated medium-Btu coal gasifier atmosphere. The compatibility of the filler materials with the chromized Cr-Mo steels, and the influence of nickel and other solute elements on the corrosion behavior of weldments are addressed. 9 refs., 8 figs., 2 tabs.