Abstract: Stress corrosion cracking which occurs in metallic portions of a high-temperature regenerative air heater can be alleviated by the disclosed methods. The methods include the step of storing a gas charge within a heated regenerative air heater, which gas charge is substantially devoid of free oxygen. The substantial absence of free oxygen from the gas charge prevents or reduces formation of nitrogen-containing oxides which typically form within an air-containing gas charge stored in a regenerative air heater held at high temperature. Conditions conducive to stress corrosion cracking are thereby alleviated by reduction of these nitrogen-containing oxides which are precursors to corrosive acids. The methods are particularly suitable for reducing stress corrosion cracking in blast furnace stoves.