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ABSTRACT. INDUSTRIAL ELECTRIC FURNACES USE THERMO-RESITANCE WITH SPECIAL CHARACTERISTICS. THESE SHOULD POSSESS A HIGH VALUE OF ELECTRIC RESISTANCE AND SUPPORT HIGH TEMPERATURES.
THIS ARTICLE PRESENTS A STUDY OF ALTERNATIVE ALLOYS TO THE COMMERCIAL ALLOYS USING NON STRATEGIC MATERIALS, WHICH ARE ABUNDANT IN BRAZIL AND HAVE REASONABLE PRICES. AFTER SOME THEORETICAL STUDIES, ALLOYS OF THE SYSTEM FE-AL-SI WAS PREPARED WITH APPROXIMATELY 5.5% OF AL AND 2% OF SI. TO THIS ALLOY SYSTEM IT WAS ADDED 1.0% OF NB, THREE DIFFERENT AMOUNT OF MO FOR A SERIES AND THREE DIFFERENT AMOUNTS OF W FOR ANOTHER SERIES.
A SERIES OF ALLOY SPECIMEN WAS OBTAINED WITH 3, 5 AND 7% OF MO AND THE OTHER SERIES WITH 3, 5 AND 7% OF W RESPECTIVELY. THE ALLOYS WERE MELTED IN A VACUUM INDUCTION FURNACE AND POWRED IN INGOTS. AFTER THAT, IT WAS FORGED TO 12500C AND HEAT TREATED.
IN THE TENSILE TEST AT ROOM TEMPERATURE, ALL THE ALLOYS PRESENTED LOW DUCTILITY AND IN THE TENSILE TEST AT 8500C TEMPERATURE ALL ALLOYS PRESENTED SATISFACTORY YIELD POINT. IN THE OXIDATION TEST FOR MASS GAIN, EXCEPT FOR THE ALLOY WITH 7% OF MO, THE ALLOYS OF THE TWO SERIES PRESENTED ABOUT THE SAME RESISTANCE.
KEYWORDS: THERMO-RESISTANCE, ALLOYS, STRATEGIC MATERIALS.
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