Effect of Boron Addition on the Transformation Behavior of Upp er Bainite in Low-carbon,Cr-Mo steel
The role of B on the isothermal bainitic transformation in low-C,lean-alloyed steel was investigated.B clearly affected both the transformation kinetics and the morphology of isothermally transformed bainite.The microstructure of bai nite formed at 500℃ consisted of a bainitic ferrite matrix and the martensite/austenite constituent.Whereas the martensite/ austenite constituent had an elongated morphology in B-free steel,the martensite/austenite constituents in the B-added steel had a granular morphology.Two types of bainite unit nucleation were considered:the initial nuclei and the nuclei formed on previously formed units.The nuclei of the bainite transformation in the B-added steel were confined to the austenite grain interior,and the bainitic ferrite nuclei had crystallographic orientations limited to K-S variants within a same Bain v ariant.The characteristic bainite microstructure in B-added steel is due to the inhibition of the bainitic ferrite nucleation at austenite grain boundaries.
Boron Grain boundary nucleation Bainitic transformation Variant selection
SONG Taejin DE COOMAN Bruno C
Graduate Institute of Ferrous Technology,Pohang University of Science and Technology,Pohang 790-784,Korea
国际会议
Asia Steel International conference 2012(第五届亚洲钢铁大会)
北京
英文
1-5
2012-09-23（万方平台首次上网日期，不代表论文的发表时间）