Measurements on the thermal expansion of fused silica

1938

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Coefficients of linear expansion for various t emperature ranges between 20 and 1,000 0 C were obtained on some llew heat-resisting alloys : An iron-chromiumaluminum alloy and three iron-chromium-aluminum-cobalt alloys. No polymorphic transition was observed in these alloys between 20 and 1,000 0 C. The alloys exhibited growth (0. 82 to 2.81 percent) after various heat treatments at t.emperatures up to 1,400 0 C. Additional heat treatments would probably cause additional growth. The densities of the mechanically worked iron-chromiumaluminum alloy and iron-chromium-aluminum-cobalt alloys increased 1.12 to 2.50 percent as a result of various heat treatments to 1,400 0 C. Tremendous grain growth occurred in the heat-resisting alloys as a result of various heat treatments at elevated t emperatures.

Section: Thermal-expansion Apparatusmentioning

confidence: 99%

“…4 Density determinations were made on the remaining pieces of the samples. These pieces (each 200 mm long) were then heated 5 to various temperatures between 1,100 and 1,400° C, held at these temperatures for various lengths of time and then cooled to room temperature.…”

Section: Growthmentioning

confidence: 99%

Thermal expansion and effects of heat treatments on the growth, density, and structure of some heat resisting alloys

1938

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“…Figure 3 of the same publication shows a sample, sample holder, and contact fingers for the vertical observation wires used in the oil bath. Tests 5 and 6 of each sample were made with the white furnace shown at the left of figure 1 of the publication by Souder and Hidnert [4]. Figure 4 of their publication indicates the method used in mOlmting each sample in the furnace.…”

Section: Apparatusmentioning

confidence: 99%

“…The precision comparator type of thermal-expansion apparatus described by Souder and Hidnert [4] was used at various temperatures between -127 0 and + 701 0 C for six tests on sample 1284 and six tests on sample 1285. Tests 1 to 4 of each sample were made with the oil bath shown at the extreme right of figure 1 of their publication.…”

Section: Apparatusmentioning

confidence: 99%

Thermal expansion of cast and of swaged chromium

1941

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Data were obtained on the linear thermal expansion of six samples of chromium (99.2 to 96.3 percent) at various temperatures between -190 0 and + 707 0 C. The expansion curves indicated anomalies at low temperatures. These anomalies were reversible on heating and cooling. The temperature at which anomalous expansion occurs appears to decrease with decrease in the purity of the chromium. Hysteresis was not observed on heating cast or swaged chromium to 300 0 C and cooling to low temperatures. Exceptionally low average coefficients of expansion were found for temperature ranges in or near the anomalous regions. The average coefficients of expansion of the samples of chromium from 20 0 C to various temperatures between 100 0 and 700 0 C lie between 5. 7X 10-6 and 10.3X 10-6 per degree centigrade.

“…The samples were investigated at various temperatures between 20 0 and 650 0 C with the precision comparator type of thermal-expansion apparatus described by Souder and Hidnert [5] . The white furnace shown at the left of figure 1 of their publication was used.…”

Section: Apparatusmentioning

confidence: 99%

Thermal expansion of some chromium-vanadium steels

1940

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Data on the linear thermal expansion of several SAE chromium-vanadium steels have been published previously. The present paper gives the results of an investigation at this Bureau on the linear thermal expansion of two other SAE chromium-vanadium steels (SAE 1625 and 6150) in the annealed condition and in the quenched and tempered condition. These steels were investigated at various temperatures between 20° and 650°0. The coefficients of expansion of the hardened sample tempered at 400°F (204°0) or SOO°F (427°0) are less than the coefficients of expansion of the annealed sample. Tempering at 1,2000F (650 0 0) 'ncreased the expansion to that of the annealed sample. For the range from 20° to 650°0, the average coefficients of expansion of all of the samples investigated vary from 13.8XlO-a to 14.SXlO-a per degree centigrade.