Hot deformation characteristics of a nitride strengthened martensitic heat resistant steel

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:590

Article

Zhang, Wen-Feng^1,2,3  Li, Xiao-Li⁴  Sha, Wei⁵  Yan, Wei²  Wang, Wei²  Shan, Yi-Yin²  Yang, Ke² 

[1] Univ Sci & Technol China, Hefei 230026, Peoples R China

[2] Chinese Acad Sci, Inst Met Res, Shenyang 110016, Peoples R China

[3] Chinese Acad Sci, Grad Sch, Beijing 100049, Peoples R China

[4] Univ Sci & Technol Liaoning, Anshan 114000, Peoples R China

[5] Queens Univ Belfast, Sch Planning Architecture & Civil Engn, Belfast BT9 5AG, Antrim, North Ireland

关键词: Steel;    Mechanical characterization;    Martensite;    Thermomechanical processing;    Recrystallization;    Phase transformation;   

DOI  :  10.1016/j.msea.2013.10.020

来源: Elsevier

【 摘 要 】

Constitutive equations including an Arrhenius term have been applied to analyze the hot deformation behavior of a nitride-strengthened (NS) martensitic heat resistant steel in temperature range of 900-1200 degrees C and strain rate range of 10(-3)-10 s(-1). On the basis of analysis of the deformation data, the stress-strain curves up to the peak were divided into four regions, in sequence, representing four processes, namely hardening, dynamic recovery (DRV), dynamic strain induced transformation (DSIT), and dynamic recrystallization (DRX), according to the inflection points in partial derivative/theta and partial derivative(partial derivative theta/partial derivative sigma)/partial derivative sigma curves. Some of the inflection points have their own meanings. For examples, the minimum of partial derivative theta/partial derivative sigma locates the start of DRV and the maximum of it indicates the start of DRX. The results also showed that the critical strain of DRX was sensitive to ln(Z) below 40, while the critical stress of DRX was sensitive to it above 40. The final microstructures under different deformation conditions were analyzed in terms of softening processes including DRV, DRX, metadynamic crystallization (MDRX) and DSIT. (C) 2013 Elsevier B.V. All rights reserved.

【 授权许可】

Free