High temperature lubricants

A process for high temperature lubrication comprises applying to the surface an oil- and grease-free aqueous solution of an alkali metal phosphate and a viscously soluble potassium polyphosphate, drying the solution and melting the residue. Preferred proportions of the melt in per cent by weight are P2O5, 55-69; Na2O 14-35; K2O, 5-27; 1 to 10% of the sodium and/or potassium can be replaced by e.g. magnesium, manganese or zinc.ALSO:High-temperature lubrication of e.g. seamless steel tubes comprises applying to their surfaces an oil- and grease-free aqueous solution of one or more alkali metal phosphates and a viscously soluble potassium polyphosphate, drying the solution and melting the residue. Preferred proportions of the melt in per cent by weight are: .P2O5...55-69 .Na2O...14-35 .K2O...5-27 1 to 10% of the sodium and/or potassium can be replaced by divalent metals, e.g. Zn, Mg or Mu. p