Ultrafine Ferrite Grains Produced by Tempering Cold-rolled Martensite in Low Carbon and Microalloyed Steels

Lan, Huifang; Liu, W. J.; Liu, X. H.

doi:10.2355/isijinternational.47.1652

Cited by 40 publications

(22 citation statements)

References 15 publications

(14 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Many techniques based on severe plastic deformation and advanced thermomechanical processing have been proposed so far for grain refinement of metallic materials [2]. Thermomechanical processing on a martensite starting microstructure is claimed to be an efficient grain refining approach in low carbon steels [3][4][5][6][7], which normally includes simple rolling that requires low reductions in thickness (~ 50%) followed by short tempering at moderate temperatures (e.g. 0.5 h at 500 °C) to produce ferrite grain size of ~ 180 nm [3].…”

Section: Introductionmentioning

confidence: 99%

“…2 The effects of tempering temperature [3], rolling reduction [4], microalloying elements [5], tempering time [6], and other deformation modes [7] have been studied so far and the main focus has been on the obtained grain sizes. However, the mechanism responsible for the formation of ultrafine microstructure is still under debate [5]. The present work aims to deal with this subject.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Toward unraveling the mechanisms responsible for the formation of ultrafine grained microstructure during tempering of cold rolled martensite

Najafi

Mirzadeh

Alibeyki

2016

Materials Science and Engineering: A

View full text Add to dashboard Cite

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Toward unraveling the mechanisms responsible for the formation of ultrafine grained microstructure during tempering of cold rolled martensite

Najafi

Mirzadeh

Alibeyki

2016

Materials Science and Engineering: A

View full text Add to dashboard Cite

“…However, very large true strain over 4 is necessarily applied to the materials in SPD process to fabricate ultrafine grain steels [2]. In recent years, some research groups reported that ultrafine ferrite grains can be obtained, without SPD, by annealing of cold-rolled martensite in low carbon steels [3][4][5], microalloyed steel [5] and maraging steel [6]. An earlier study reported that the heavily deformation of lath martensite in low carbon steels can produce very fine austenite grain structure in the process of austenitizing [7].…”

Section: Introductionmentioning

confidence: 99%

Warm deformation behavior of quenched medium carbon steel and its effect on microstructure and mechanical properties

Wang

Tian

et al. 2009

Materials Science and Engineering: A

View full text Add to dashboard Cite

“…By martensite transformation, the martensite packets and blocks divided the prior austenite grain into several regions with high angle boundaries, effectively refining the microstructure [8] . And by cold rolling, the dislocation cells were generated with larger boundary misorientation, which evolved into ultrafine grains during the subsequent tempering process with sharp and highly misoriented grain boundaries [9] . This method, taking martensite as initial microstructure, achieved large accumulative deformation through conventional cold rolling, revealing prospects for practical application.…”

mentioning

confidence: 99%

High performance low cost steels with ultrafine grained and multi-phased microstructure

Lan

et al. 2009

Sci. China Ser. E-Technol. Sci.

View full text Add to dashboard Cite

Ultrafine grained ferrite was obtained through tempering cold rolled martensite with an average grain size of 200-400 nm in a low carbon and a microalloyed steel. Thermal and mechanical stability of the two steels was studied. Due to the pinning effect of microalloyed precipitates on the movement of dislocations and grain boundaries, the recrystallization and grain growth rate were retarded, and the thermal stability of ultrafine grained microstructure was improved. The ultrafine grained ferritic steel was strengthened, but its strain hardening rate was reduced. It seems that the tiny carbide precipitates have no significant effect on work hardening rate. The ultrafine grained ferrite+martensite dual phase microstructure was obtained in the microalloyed steel through intercritically annealing cold rolled martensite. The resulting multiphase microstructure has a tensile strength higher than 1.0 GPa with a yield ratio lower than 0.7. Another type of multiphase microstructure with nanoscaled lath bainite+ retained austenite was obtained through an isothermal heat treatment in low temperature bainite transformation region in high carbon steel. The tensile strength was as high as 1.64 GPa with a yield ratio of 0.84. ultrafine grained steel, multiphase, high strength, yield ratio Under the situations of the global shortage of natural resources and the substantial fluctuation of energy cost, it is more important than ever to use advanced technology to realize energy and material saving, to reduce emission and to operate an environment friendly steel industry with sustainable development. In the field of steel rolling, it is necessary to produce new generations of steel products with high performance low cost (HPLC) by using the most economical technology in terms of processing optimization, product development and technology upgrading.One of the HPLC materials that have great commercial potential is the ultrafine grained steels. Ultrafine grained (UFG) materials and their production methods have received extensive attention from material scientists during the past decades. Most existing methods for producing UFG structure are based on severe plastic deformation (SPD), such as equal channel angular pressing (ECAP) [1,2] , accumulative roll-bonding (ARB) [3,4] and so on. Although these methods are capable of obtaining submicron or nano-scaled microstructure, the need of using special equipments to achieve the necessary huge accumulative strain makes them inadequate and uneconomic in mass production of UFG materials.Tsuji et al. [5][6][7] fabricated ultrafine grained steels through tempering cold rolled martensite. By martensite transformation, the martensite packets and blocks divided the prior austenite grain into several regions with high angle boundaries, effectively refining the microstructure [8] . And by cold rolling, the dislocation cells were generated with larger boundary misorientation, which evolved into ultrafine grains during the subsequent tem-

show abstract

Ultrafine Ferrite Grains Produced by Tempering Cold-rolled Martensite in Low Carbon and Microalloyed Steels

Cited by 40 publications

References 15 publications

Toward unraveling the mechanisms responsible for the formation of ultrafine grained microstructure during tempering of cold rolled martensite

Toward unraveling the mechanisms responsible for the formation of ultrafine grained microstructure during tempering of cold rolled martensite

Warm deformation behavior of quenched medium carbon steel and its effect on microstructure and mechanical properties

High performance low cost steels with ultrafine grained and multi-phased microstructure

Contact Info

Product

Resources

About