Selecting the Right Alloy

The Right Alloy Extends Product Life

The Direct Reduction of Iron (DRI) process uses hydrogen to reduce iron, usually pellets, from Fe2O3 to FeO in a reactor. The reduced pellets are melted to produce steel. The DRI process uses stainless steel reformer tubes and fittings to produce hydrogen, and also in the reactor’s gas pre-heater. In some pre-heaters, metal dusting, or carburization, was causing premature failure of tubes and elbows due reactor exhaust gas. MetalTek had witnessed and helped solve a similar metal dusting condition for a hydrogen reformer customer in Chile. Applying that experience, MetalTek suggested a material change to a more carburization resistant 35 chrome, 45 nickel microalloy. The customer tested the alloy in their preheater furnaces, approved and adopted it. Furnace coils that previously had to be replaced on a regular basis, now operate for many years with little or no metal dusting.