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Some aspects of possible bearing steel microstructure modifications
Author(s) -
Dlouhý Ivo,
x;karek Jix;í,
Habrovec Frantix;ek
Publication year - 1994
Publication title -
steel research
Language(s) - English
Resource type - Journals
eISSN - 1869-344X
pISSN - 0177-4832
DOI - 10.1002/srin.199401183
Subject(s) - austenite , metallurgy , martensite , materials science , tempering , quenching (fluorescence) , toughness , ferrite (magnet) , microstructure , composite material , physics , quantum mechanics , fluorescence
Microstructural changes and mechanical properties with Mn‐Cr steel (0.65 % C) under effect of cold rolling, rapid austenitizing, immediate oil quenching and low temperature tempering were investigated. Compared to properties of conventionally treated standard Cr‐C bearing steel, higher ultimate strength, increased fracture toughness and enhanced rolling contact fatigue life were observed at comparable yield stress levels. The increased stress relaxation ability of the lath martensite matrix, and the absence of transformation microcracks, both due to the reduced carbon content in steel and also in γ‐solid solution, are the main reasons of the properties' improvement. The double transfer of substructural defects from cold worked ferrite to austenite and back into martensite, and the austenite heterogeneity control, both enabled by rapid austenitizing followed by quenching, was the key for obtaining the effects mentioned.