AISI/DOE Technology Roadmap Program: Cold Work Embrittlement of Interstitial Free Steel

Bowker, John T ; Martin, Pierre

American Iron and Steele Institute (United States)

关键词: Fractures;    Embrittlement;    36 Materials Science;    Interstitials;    Microstructure;   

DOI  :  10.2172/805761
RP-ID  :  DOE/ID/13554/TPR9756
RP-ID  :  FC07-97ID13554
RP-ID  :  805761

美国|英语

来源: UNT Digital Library

【 摘 要 】

This work addresses the issues of measurement of secondary cold work embrittlement (SCWE) of an IF steel in deep-drawn parts using laboratory tests, and its correlation with real part fracture. It aimed at evaluating the influence of the steel chemistry and processing condition, microstructure, and test conditions, on SCWE as well as the effect of SCWE on fatigue properties. Size 6-in. cups produced with various draw ratios or trimmed at different heights were tested to determine the ductile-to-brittle-transition temperature (DBTT) as a function of strain. The 2-in. cup/expansion test, bend test and fracture of notched specimens were also used to generate information complementary to that provided by the 6-inch cup/expansion test. The relationship between laboratory tests and fracture in real parts was established by testing large-scale parts. The fatigue behavior was investigated in the as-rolled and deep drawn (high stain) conditions, using prestrained specimens taken from the wall of a formed part.