Heat resistant phosphate coatings, methods and articles produced therefrom

Claim 1

A METHOD OF FORMING HEAT RESISTANT COATING ON A SURFACE OF FERROUS METAL AND ALLOYS THEREOF COMPRISING CONTACTING SAID SURFACE WITH A SOLUTION CONTAINING AS THE ESSENTIAL COATING PRODUCING INGREDIENTS BETWEEN ABOUT 70 GRAMS PO4 PER LITER AND 400 GRAMS PO4 PER LITER OF CALCIUM MONOPHOSPHATE, AN AMOUNT OF PHOSPHORIC ACID SUFFICIENT TO PREVENT THE FORMATION OF A PRECIPITATE FROM THE SAID MONOPHOSPHATE IN SAID SOLUTION, AND UP TO 50% BASED ON SAID MONOPHOSPHATE OF A THERMALLY DECOMPOSABLE PHOSPHATE SELECTED FROM THE GROUP CONSISTING OF AMMONIUM PHOSPHATE, UREA PHOSPHATE AND ANILINE PHOSPHATE, SAID THERMALLY DECOMPOSABLE PHOSPHATE BEING PRESENT IN CONCENTRATIONS ALWAYS LESS THAN 115 GRAMS PO4 PER LITER, AND THEREAFTER SUBJECTING SAID SURFACE TO TEMPERATURES BETWEEN ABOUT 300*C. TO 1200*C. FOR A PERIOD OF TIME SUFFICIENT TO YIELD A FIRMLY ADHERENT PHOSPHATE COATING ON SAID SURFACE.

Claim 2

A METHOD OF FORMING HEAT RESISTANT COATING ON A SURFACE OF FERROUS METAL AND ALLOYS THEREOF COMPRISING CONTACTING SAID SURFACE WITH A SOLUTION CONTAINING AS THE ESSENTIAL COATING PRODUCING INGREDIENTS BETWEEN ABOUT 70 GRAMS PO4 PER LITER AND 400 GRAMS PO4 PER LITER OF CALCIUM MONOPHOSPHATE, AN AMOUNT OF PHOSPHORIC ACID SUFFICIENT TO PREVENT THE FORMATION OF A PRECIPITATE FROM THE SAID MONOPHOSPHATE IN SAID SOLUTION, AND UP TO 50% BASED ON SAID MONOPHOSPHATE OF A THERMALLY DECOMPOSABLE PHOSPHATE SELECTED FROM THE GROUP CONSISTING OF AMMONIUM PHOSPHATE, UREA PHOSPHATE AND ANILINE PHOSPHATE, SAID THERMALLY DECOMPOSABLE PHOSPHATE BEING PRESENT IN CONCENTRATIONS ALWAYS LESS THAN 115 GRAMS PO4 PER LITER, AND THEREAFTER SUBJECTING SAID SURFACE TO TEMPERATURES BETWEEN ABOUT 300*C. TO 1200*C. FOR A PERIOD OF TIME SUFFICIENT TO YIELD A FIRMLY ADHERENT PHOSPHATE COATING ON SAID SURFACE.