Ferrite recrystallisation and intercritical annealing of cold-rolled low alloy medium carbon steel

Abstract

Static recrystallisation of cold-rolled AISI 4130 medium carbon steel in the ferritic regime and its response to intercritical annealing treatment are studied. A fine and recrystallised microstructure with improved mechanical properties is obtained via subcritical annealing of cold-rolled sheet, where the subsequent intercritical annealing results in the enhancement of tensile strength via the formation of dual-phase microstructure. Intercritical annealing of the cold-rolled sheet is characterised by an initial drop in hardness due to recrystallisation and subsequent rise in hardness as a result of austenitisation. It is revealed that continuous martensite phase can result in a higher deformation resistance. Finally, the effects of intercritical annealing at temperatures below pearlite dissolution finish temperature (Ac_1f) are discussed.

KEYWORDS:

• AISI 4130 steel
• ferrite recrystallisation
• intercritical annealing
• mechanical properties

Acknowledgement

The authors would like to greatly thank the members of the Advanced Steels and Thermomechanically Processed Engineering Materials Laboratory for their help and support.

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Hamed Mirzadeh http://orcid.org/0000-0001-7179-0052

Mehran Zamani http://orcid.org/0000-0002-3369-8738