Thermal expansion of heat resisting alloys: Nickel-Chromium, iron-chromium, and nickel-chromium-iron alloys

Abstract

This paper gives data on the linear thermal expansion of various heat-resisting alloys (nickel-chromium, iron-chromium, and nickel-chromium-iron alloys). The alloys contain to 77 per cent nickel, 5 to 27 per cent chromium, and to 82 per cent iron. The coefficients of expansion of the alloys were determined for various temperature ranges between 20° and 1,000° C, and the effects due to temperature, chemical composition, heat treatment, etc., were determined. Critical regions were located on the thermal expansion curves of some of the alloys. For a given temperature range, the coefficients of expansion of nickel-chromium alloys containing from to about 20 per cent chromium are nearly the same. The effects of chromium content, carbon content, heat treatment, etc., on the coefficients of expansion of iron-chromium alloys for various temperature ranges are indicated in a figure. The results on the thermal expansion of nickel-chromium-iron alloys were correlated with the structure of the alloys. Transformations from one phase to another caused significant changes in thermal expansion. The expansion curves on the first heating of nearly all of the cast nickel-chromium-iron alloys indicate a retardation or decrease in expansion between 700° and 800° C, due to precipitation of carbide.