Effect of Temperature on the Microstructural Changes of HK–40 Reformer Tube Materials

Abstract

In situ metallography has been used to study the effect of temperature on the microstructural changes on the outside surface of primary reformer tubes, used for the production of reformed gas suitable for ammonia synthesis in a 200 tonnes per day capacity ammonia plant. The outside skin temperature varied in the range of 860° to 1050°C. The studies indicated marked changes with increasing temperature in the size of grains and carbide morphology, i.e., the pattern and distribution of primary and secondary carbides.