Abstract: The chloride corrosion threshold of a metal embedded in a cementitious structure is determined in an accelerated manner by using an electric field to increase the rate of migration of chloride ion into the structure and monitoring the interface between the metal and the cementitious material to detect the onset of corrosion, then determining the chloride corrosion threshold, which is defined as the chloride content of the cementitious material once corrosion has begun. This determination can be performed over a time period of as little as 2 to 3 weeks rather than the months or years required by conventional chloride corrosion test procedures.

Abstract: Alloy steels that combine high strength and toughness with high corrosion resistance are achieved by a dislocated lath microstructure, in which dislocated martensite laths that are substantially free of twinning alternate with thin films of retained austenite, with an absence of autotempered carbides, nitrides and carbonitrides in both the dislocated martensite laths and the retained austenite films. This microstructure is achieved by selecting an alloy composition whose martensite start temperature is 350° C. or greater, and by selecting a cooling regime from the austenite phase through the martensite transition region that avoids regions in which autotempering occurs.