Abstract
Changes in electrical resistance accompanying transformations in steels with magnetic change (e.g. ฮณ โ martensite/bainite) and without magnetic change (e.g. ฮณ โ ฮฑ, above Curie temperature) have been examined; the former class affects the resistivity the latter does not. Next, while the efficacy of electrical resistivity measurement in capturing the wellโknown features of austenite stabilization (e.g. over โ ageing, reversibility, and influence of prior martensite amount and so on) in high carbon steels has been reported in an earlier publication, new features (e.g. increase in resistance โincrease at very low temperatures, change in temperature coโefficient of resistivity in the stabilized material etc.) are highlighted here. Finally, the work shows that a quantitative estimate of precipitation in the copper bearing, ageโhardenable HSLAโ100 steel during tempering can be done by continuous electrical resistivity measurement. These data also allow an inโdepth kinetic analysis using the JohnsonโMehlโAvrami equation.