Continuous decarburization annealing with recycle to convert carbon monoxide

摘要

In the decarburization annealing of steel strip, wherein the annealing atmosphere flows counter to the strip motion in the furnace, there is an undesirable buildup of carbon monoxide in the zone where the strip enters the furnace. Carbon monoxide is undesirable because it slows the decarburization of the strip by a back reaction. The carbon monoxide is removed from the buildup zone and catalytically converted to methane and water by a known reaction with hydrogen, and the water and methane are in-turn recycled near the buildup zone of the furnace. It was found that the presence of water at temperatures up to 1600 DEG F. prevents methane from acting as a carburizing agent.