摘要
This study analyzes the evolution of carbides in the tempering process of a newly developed semi-high speed steel cold forged roll with nitrogen addition using a transmission electron microscope （TEM） equipped with an energy dispersive X-ray （EDX）. The precipitation sequence of the carbides was identified in the entire tempering process and it can be expressed as M3C→M3C ＋ M （C, N）Ⅱ→M（ C, N）Ⅱ → M7C3Ⅱ ＋ M23 C6. The secondary hardening in the tempering process was mainly due to the dispersed precipitation of fine M（ C, N）n particles. The dissolution of M3 C tempered at high temperatures induced the precipitation and coarsening of M7 C31/ and M23 C6.
This study analyzes the evolution of carbides in the tempering process of a newly developed semi-high speed steel cold forged roll with nitrogen addition using a transmission electron microscope （TEM） equipped with an energy dispersive X-ray （EDX）. The precipitation sequence of the carbides was identified in the entire tempering process and it can be expressed as M3C→M3C ＋ M （C, N）Ⅱ→M（ C, N）Ⅱ → M7C3Ⅱ ＋ M23 C6. The secondary hardening in the tempering process was mainly due to the dispersed precipitation of fine M（ C, N）n particles. The dissolution of M3 C tempered at high temperatures induced the precipitation and coarsening of M7 C31/ and M23 C6.
基金
supported by the Baosteel Group Corporation Project (R05DSES220)
