BOILER TUBE WITH CORROSION-RESISTANT AND WEAR-RESISTANT SURFACE FLAME-SPRAYED LAYER

摘要

PROBLEM TO BE SOLVED: To improve corrosion resistance and wear resistance and to improve durability by forming a flame-sprayed layer wherein hole sealing treatment for densifying the tissue is performed on the surface in a boiler tube being exposed with an acidic gas and stem such as sulfur dioxide gas and hydrogen chloride gas. ;SOLUTION: This boiler tube with improved durability has a flame-sprayed layer wherein hole sealing treatment for densifying the tissue on its surface during a process for forming a corrosion-resistant and wear-resistant surface flame-sprayed layer in taking densifying of the flame-sprayed film on the surface into the consideration. Namely, during a process for forming a flame-sprayed film of any one of a chromium carbide-contg. cermet, Hastelloy alloy or an Inconel alloy, hole sealing treatment is performed by using at least one kind of either inorg. hole sealing agents such as chromic acid, metal alkoxide alcohol and silicate types forming metal oxides or org. hole sealing agents such as fluororesin, polysiloxane, etc., types forming heat-resistant compd. to form a tissue-densified flame-sprayed layer.;COPYRIGHT: (C)1997,JPO