کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1447443 988644 2011 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Ultrafine ferrite formation through isothermal static phase transformation
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
Ultrafine ferrite formation through isothermal static phase transformation
چکیده انگلیسی

A novel thermomechanical route has been developed to produce an ultrafine-grained structure through warm deformation of metastable austenite followed by isothermal static transformation to ferrite. The thermomechanical parameters influenced the evolution of ferrite phase transformation (i.e. nucleation and growth), resulting in different levels of ferrite grain refinement. For the first time grains as fine as 200 nm were produced through a traditional diffusional transformation of austenite to ferrite. The use of a model Ni–30Fe austenitic alloy showed that the strain has a strong effect on the nature of the intragranular defects developed throughout the microstructure. At a low strain, microbands were the dominant intragranular features. There was a transition strain above which a complex cell/subgrain substructure with high misorientation angle appeared in the vicinity of prior austenite grain boundaries. This region was extended with strain and promoted significant ferrite nucleation sites at an early stage of phase transformation, resulting in the local formation of nanosized ferrite grains near the prior austenite grain boundaries with ultrafine grains towards the interior of the original austenite grain.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Acta Materialia - Volume 59, Issue 10, June 2011, Pages 4186–4196
نویسندگان
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