Reducing the high-temperature loss of steel in furnaces

Abstract

Assessment of the loss of steel in industrial furnaces may be based on the scale thickness. Means of reducing the oxidation of steel are evaluated. Special attention is paid to the difficulty of reducing the steel loss on account of decrease in the oxidant consumption n. Nonoxidative heating of steel in industrial furnaces is shown to be feasible at present. The requirements here are practically molecular mixing of the components in primary combustion (for natural gas with air excess n = 0.48–0.5); synchronous burner operation and constraints on the oxidation n with regulation of the primary fuel combustion (Δn ≤ 0.01); and effective choking of the primary gas flux so as to rule out inverse circulatory motion of the products of incomplete primary combustion from their combustion zone into the metal-heating zone. Design approaches and operating conditions for forging and rolling furnaces are proposed, so as to reduce or suppress steel losses. Particular attention is paid to the internal high-temperature oxidation of silicon in transformer steel and the decarburizing heating of ball-bearing steel.