Spall-resistant steel tubing or other steel articles subjected to high temperature steam and method

摘要

A process is disclosed herein in which the inner surface of a ferritic steel tube is subjected to relatively high temperature steam for a period of time, thereby resulting in the formation of a duplex scale layer of steam-grown oxide at the inner surface. As also disclosed herein, the steel tubing is pretreated so as to form a diffusion barrier at the center of the duplex layer. This barrier serves to retard the rate at which the duplex layer forms, thereby reducing the chances that the scale will grow to sufficient thickness that it will spall in response to thermal stress as the tube is placed into and taken out of service.