METHOD FOR SURFACE TREATING A HEAT EXCHANGER, SURFACE TREATMENT AGENT, AND ALUMINUM HEAT EXCHANGER

摘要

A method for surface treating a heat exchanger and an aluminum heat exchanger obtained from this method are provided that can effectively suppress the foul odor characteristic to flux that emanates following degradation of a hydrophilic coating film and a chemical conversion coating film in a non-corrosive flux brazed heat exchanger on which flux easily remains. The method for surface treating a non-corrosive flux brazed heat exchanger made of an aluminum material conducts a pickling treatment step, a chemical conversion treatment step, and a deodorizing treatment step on the heat exchanger, in which the acidic cleaning agent contains nitric acid and sulfuric acid as well as a predetermined amount of ferric salt, and the surface treatment agent contains silica grains coated by a vinyl alcohol polymer and polyallylamine resin such that the total content of the silica grains and the vinyl alcohol polymer is a predetermined amount.