| abstract |
The invention relates to low-viscosity, aqueous coolant brines based on inhibited alkali metal acetates and/or formates having improved corrosion protection, wherein the coolant brines contain 0.2 to 5% by weight of alkali metal sulfites or pyrosulfites, in particular 1 to 2.5% by weight of these sulfites. The brines according to the invention furthermore contain 0.3 to 5% by weight of basic substances from the alkali metal carbonates, hydroxides, borates and phosphates group and also 0 to 0.3% by weight of alkali metal silicates and 0.02 to 0.2% by weight of stabilizers from the triazoles, benzimidazoles and/or mercaptothiazoles group. The novel coolant brines result in very low corrosion rates, in particular with steel and cast iron. |