A METHOD FOR PREVENTION OF SCALE FORMATION ON ALLOY PIPES BENDS USED IN BOILERS DURING POST HEAT TREATMENT PROCESS OF THE BENDS IN HEAT TREATMENT FURNACES

摘要

The invention relates to a method for prevention of scale formation on alloy pipes bends used in boilers during post heat treatment process of the bends in heat treatment furnaces, comprising the steps of: providing a tubular member according to pre-determined size, thickness, and outer diameter for forming a tube bend of a boiler; loading the tubular member on an incremental bending machine and assign the radius and angle of the bend to be formed; unloading the bend member from the machine and applying a coating of calcium carbonate powder on the surface of the member; placing the coated member in a heat treatment furnace maintained at an elevated temperature of 1050�C for heating, normalizing, and tempering, wherein the coating is formed by mixing chalk powder in a ratio of 3:2 at room temperature, and wherein the thickness of the coating is maintained between 500 microns and 1000 microns.