ISSN:
1573-8973
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Conclusions 1. It was found that the structure of steels 22F1B, 27F1B, and 35F2B resulting from isothermal transformation of supercooled austenite at 680–720°C consists of evenly distributed high-strength, oriented, dispersed vanadium carbide in a ferrite matrix. Such vanadium carbides impart high strength at normal and elevated temperatures, while ferrite provides fairly high ductility. 2. The structure of the steels after the double heat treatment (normalization at 1130°C for 5 min, tempering at 720°C for 3 h) consists of ferrite and unevenly distributed vanadium carbides. The strength characteristics at normal and elevated temperatures are lower than after the isothermal treatment at 680–720°C for 30 min. 3. The original structure of the steel after quenching or after isothermal treatment has different effects on the hardness during subsequent tempering. Tempering at 400–450°C after quenching or incomplete decomposition of supercooled austenite leads to reduction of the hardness due to coalescence of cementite, while complete decomposition of austenite, with formation of a ferrite-carbide structure, leads to an increase in hardness beginning at very low temperatures.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00664176
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