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A contribution to the increase in yield strength during the bake hardening process
Author(s) -
Kozeschnik Ernst,
Buchmayr Bruno
Publication year - 1997
Publication title -
steel research
Language(s) - English
Resource type - Journals
eISSN - 1869-344X
pISSN - 0177-4832
DOI - 10.1002/srin.199701783
Subject(s) - carbide , materials science , precipitation hardening , metallurgy , ternary operation , hardening (computing) , work hardening , precipitation , thermal , yield (engineering) , composite material , thermodynamics , microstructure , physics , layer (electronics) , computer science , meteorology , programming language
Bake hardening denotes the controlled aging of steels during a thermal treatment as applied for example by paint baking outer panels of automobiles. Dependent on the duration of the thermal exposure and the temperature, the increase in yield strength can reach up to 80 MPa. The temporal progress is a function of the steel composition and the degree of prestrain and can appear in one or two stages. It seems that the interaction between precipitating ternary iron carbides and the formation of Cottrell atmospheres around mobile dislocations count responsible for the different shapes of the precipitation curves. In the present work an attempt is made to simulate the atmosphere forming and carbide precipitation with the use of classical models and take into account the degree of prestrain. The results are then compared with experimental data on the bake hardening process.