Isothermal Recrystallization Behavior of Cold-deformed Martensite in an Ultra-low-carbon Microalloyed Steel
نویسندگان
چکیده مقاله:
One of the most promising ways to produce a grain-refined microstructure in some steel materials is the thermomechanical processing route of subcritical recrystallization annealing of a cold-deformed martensite structure. In the present study, the microstructural evolutions and the associated recrystallization kinetics under various subcritical annealing heat treatment conditions are explored in an API X120 grade, advanced, High-Strength, Low-Alloy (HSLA) steel with an initial cold-deformed martensite microstructure. The steel sheet was the subject of a conventional cold rolling process for moderate true strain of 60% followed by isothermal recrystallization for different temperature-time combinations. Optical microscopy and scanning electron microscopy were used to characterize the microstructural evolutions, and the recrystallization kinetics was evaluated by hardness measurements with the aid of the Johnson-Mehl-Avrami-Kolmogorov (JMAK) relationship. The experimental results indicated that annealing at 948 K (675 °C) for 18 h is the optimum condition to achieve a grain-refined ferrite microstructure with an averaged grain size of 5.2 µm. The slow kinetics of recrystallization was also revealed by JMAK model as the Avrami exponent was calculated around one for all of the experiments. These observations are rationalized in part by the possible formation of microalloying elements carbides during the annealing process in association with the existence of the inhomogeneously deformed initial microstructure. This results in the appearance of a continuous regime for the recrystallization nucleation along with the sluggish movement of recrystallization fronts.
منابع مشابه
Recrystallization Behavior of Deep Drawing Low Carbon Steel Sheets Produced by Mobarakeh Steel Plant
In the present work the recrystallization behavior of deep drawing grade Al-killed low carbon steel sheets produced by Mobarakeh Steel Plant (MSP) has been studied. Salt bath isothermal annealing has b...
متن کاملrecrystallization behavior of deep drawing low carbon steel sheets produced by mobarakeh steel plant
in the present work the recrystallization behavior of deep drawing grade al-killed low carbon steel sheets produced by mobarakeh steel plant (msp) has been studied. salt bath isothermal annealing has been applied to cold rolled samples and the resulted microstrucrures have been compared with the microstructure obtained from the box annealing process in msp. it is found that at 635 and 700ºc the...
متن کاملTexture Evolution in Low Carbon Steel Fabricated by Multi-directional Forging of the Martensite Starting Structuree
It has been clarified that deformation and annealing of martensite starting structure can produce ultrafine-grained structure in low carbon steel. This study aims to investigate the texture evolution and mechanical properties of samples with martensite structure deformed by two different forging processes. The martensitic steel samples were forged by plane strain compression and multi-directio...
متن کاملLow temperature superplasticity and thermal stability of a nanostructured low-carbon microalloyed steel
We describe here for the first time the low temperature superplasticity of nanostructured low carbon steel (microalloyed with V, N, Mn, Al, Si, and Ni). Low carbon nanograined/ultrafine-grained (NG/UFG) bulk steel was processed using a combination of cold-rolling and annealing of martensite. The complex microstructure of NG/UFG ferrite and 50-80 nm cementite exhibited high thermal stability at ...
متن کاملCrystallographic Analysis of Lath Martensite in Ferrite-Martensite Dual Phase Steel Sheet Annealed after Cold-Rolling
The martensite steels produced by quenching and tempering has been used for machine structural use. Martensite in ferrite-martensite dual-phase steels (hereinafter, DP steels) also has important roll in strengthening of the automobile steel sheets. Therefore the importance of analyzing the microstructure and their mechanical properties of the martensite has been increased year by year. Many res...
متن کاملمنابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ذخیره در منابع من قبلا به منابع من ذحیره شده{@ msg_add @}
عنوان ژورنال
دوره 16 شماره 1
صفحات 1- 11
تاریخ انتشار 2019-07-01
با دنبال کردن یک ژورنال هنگامی که شماره جدید این ژورنال منتشر می شود به شما از طریق ایمیل اطلاع داده می شود.
میزبانی شده توسط پلتفرم ابری doprax.com
copyright © 2015-2023