Continuous caster corrosion

The causes of damage which commonly occurs within continuous caster spray chambers and at runout tables will be described. Corrosion of carbon steel components, particularly structural members will be emphasized. Information has been compiled through field inspections, failure analyses, and through analyses of water, deposits and corrosion products collected from several different casters. Oxygen corrosion of carbon steels may occur to varying degrees depending on system design and operating conditions. Acid corrosion has been identified within spray chambers of many casters which use mold powders. Components exposed to acid may corrode at alarming rates. Laboratory and field data correlates the usage of certain mold powders with spray water alkalinity and pH reduction. Corrosion control methods are described, including chemical treatment of spray water, the use of alternate materials, coatings and shielding, and the judicious use of mold powders. A laboratory test procedure has been developed to measure the effects of heated mold powder by-products on water alkalinity. Information from such testing may be used for corrosion control by aiding in the chemical treatment of spray waters and/or in the selection of mold powders.