Premium
Influence of Residual Elements on Mechanical Properties of Two Carbon Steel Grades
Author(s) -
Xu Su,
Brown Jim R.,
Tyson William R.
Publication year - 2006
Publication title -
steel research international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.603
H-Index - 49
eISSN - 1869-344X
pISSN - 1611-3683
DOI - 10.1002/srin.200606468
Subject(s) - charpy impact test , materials science , microstructure , metallurgy , ultimate tensile strength , toughness , ferrite (magnet) , grain size , carbon fibers , ductility (earth science) , hardening (computing) , carbon steel , composite material , corrosion , creep , layer (electronics) , composite number
Experiments were carried out to study the influence of residual elements on microstructure and mechanical properties of two carbon steel grades (i.e. 0.04% C and 0.20% C). The effect of residuals on the microstructure of the carbon steels was mainly to decrease ferrite grain sizes. The effect of residuals on tensile properties was mainly to increase yield and tensile strengths and to slightly decrease ductility, which reflected a combination of solid solution hardening by residuals and grain refinement. The 40 J notch toughness transition temperature (TT) was determined by fitting Charpy absorbed energies to a hyperbolic function and by finding the temperature corresponding to 40 J in the fitted curve; a statistical analysis was performed to ensure the repeatability of TTs defined by this procedure. After the step‐cooling heat treatment to maximize segregation, the 40 J TT of a 0.04% C steel with high Mn and Si contents increased by 28K and the 40 J TT of 0.20 % C steels with the highest residual level (0.085% Sn, 0.4% Cu and 0.4% Ni) increased by 24K, indicating that the upward shift of TT is small even for high levels of residuals. Grain boundary segregation was semi‐quantitatively analysed by Auger electron spectroscopy. Small amounts of Sn segregation were observed, most notably in the low‐C grade.