TY - JOUR
T1 - Correlation between the intergranular brittleness and precipitation reactions during isothermal aging of an Fe-Ni-Mn maraging steel
AU - Hossein Nedjad, S.
AU - Nili Ahmadabadi, M.
AU - Furuhara, T.
PY - 2008/8/25
Y1 - 2008/8/25
N2 - Evolution of the intergranular brittleness of an Fe-10Ni-7Mn (weight pct) maraging steel was correlated with precipitation reactions during isothermal aging at 753 K. Intergranular brittleness of the Fe-Ni-Mn steel raises after aging treatment which occurs catastrophically at zero tensile elongation in the underaged and peakaged steels. The intergranular failure is attributed to grain boundary weakening due to the formation of coarse grain boundary precipitates associated with solute-depleted precipitate-free zones during isothermal aging. Further, evidences of planar slip bands were found within the grains of a peakaged specimen loaded by tensile deformation. Those inhomogeneously deformed bands were identified to apply large strain localization in the soft precipitate-free zones at grain boundaries which is assumed to fascinate microcracks initiation at negligible macroscopic strains in the underaged and peakaged steels. During further aging, concurrent reactions including (i) overaging of matrix precipitates, (ii) spheroidization of grain boundary precipitates, (iii) growth of precipitate-free zone in width and (iv) diffusional transformation to austenite take place which increase tensile ductility after prolonged aging.
AB - Evolution of the intergranular brittleness of an Fe-10Ni-7Mn (weight pct) maraging steel was correlated with precipitation reactions during isothermal aging at 753 K. Intergranular brittleness of the Fe-Ni-Mn steel raises after aging treatment which occurs catastrophically at zero tensile elongation in the underaged and peakaged steels. The intergranular failure is attributed to grain boundary weakening due to the formation of coarse grain boundary precipitates associated with solute-depleted precipitate-free zones during isothermal aging. Further, evidences of planar slip bands were found within the grains of a peakaged specimen loaded by tensile deformation. Those inhomogeneously deformed bands were identified to apply large strain localization in the soft precipitate-free zones at grain boundaries which is assumed to fascinate microcracks initiation at negligible macroscopic strains in the underaged and peakaged steels. During further aging, concurrent reactions including (i) overaging of matrix precipitates, (ii) spheroidization of grain boundary precipitates, (iii) growth of precipitate-free zone in width and (iv) diffusional transformation to austenite take place which increase tensile ductility after prolonged aging.
KW - Grain boundary precipitation
KW - Intergranular brittleness
KW - Maraging steel
KW - Planar slip
KW - Precipitate-free zone
UR - http://www.scopus.com/inward/record.url?scp=45249092533&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=45249092533&partnerID=8YFLogxK
U2 - 10.1016/j.msea.2008.01.070
DO - 10.1016/j.msea.2008.01.070
M3 - Article
AN - SCOPUS:45249092533
SN - 0921-5093
VL - 490
SP - 105
EP - 112
JO - Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing
JF - Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing
IS - 1-2
ER -