recalescence

Reglow, rē-glō′, v.i. to recalesce.—n. recalescence.

Experiments by himself and other observers have shown that the temperatures at which iron and nickel lose their magnetic properties depend on the specimens used and the magnetizing forces employed; but the temperatures at which they begin to lose these properties are definite—for nickel about 300� C., and iron about 680� C. The author's own experiments on "Recalescence of Iron" show two critical temperatures; and Pinchon has shown by calorimetric measurement that between 660� and 720� C., and between 1,000� and 1,050� C., heat becomes latent.

Lectures on the kinetic theory of gases should have a parallel course in which the classical experiments of the senior heat laboratory are performed,—such experiments, for example, as vapor density, resistance and thermocouple pyrometry, bomb calorimetry viscosity, molecular conductivity, freezing and boiling points, recalescence, etc.

The process consists in heating the steel quickly to 200° or more above the upper critical, cooling in air down through the recalescence point, then reheating it to just above the critical point and again cooling slowly through the recalescence, then quenching in oil.