Determination of processing maps for the warm working of vanadium microalloyed eutectoid steels

Ironmaking & Steelmaking

et al. 2019

The effects of cooling modes (air, furnace and water) on the variation of microstructure and mechanical properties of medium carbon steel were investigated. SEM, TEM and EBSD techniques were used to observe the microstructure. The observed results show that the effect of cooling mode on the grain size is insignificant. The average sizes of ferrite grain obtained under different cooling modes were little different. Moreover, in all the cases, most of the cementite lamellas were transformed into cementite particles, except for some of the residual cementite lamellas which were present on the original pearlite colonies. It has also been found that the ferrite substructure and precipitation of cementite particles are significantly affected by the cooling modes. Compared to other cooling modes, the furnace cooling is beneficial to the homogeneity of microstructure. The particles are distributed on the ferrite matrix more homogeneously after furnace cooling which results in a better combination of strength and ductility.

Section: Discussionmentioning

confidence: 99%

Effect of cooling mode on the microstructure and mechanical properties of medium carbon steel after warm rolling

Fan

Ironmaking & Steelmaking

et al. 2019

“…The carbide particles may be composed of the residual short rod-like cementite and the precipitated carbide particles. Before the reversal austenization, the initial lamellas were broken, distorted and bended during warm deformation [38,39]. Some cementite lamellas transformed into carbide particles, while the other transformed into the short rod-like.…”

Section: Submicron Ferrite Grains Formationmentioning

confidence: 99%

Ultra-fine-Grained Ferrite Prepared from Dynamic Reversal Austenite During Warm Deformation

Acta Metall. Sin. (Engl. Lett.)

Yaqiang

et al. 2019

The ultra-fine-grained ferrite (UFGF) with the size of less than 1 μm is often difficult to be obtained for low-alloyed steel in practical production processing. In this study, considering the rod and wire production process, a new method for preparing the UFGF with submicron scale is proposed by warm deformation of six passes with total strain of 2.6, followed by the cooling process in Gleeble-3500 thermo-mechanical simulator. The results show that the UFGF with an average size of 0.64 μm could be obtained via the phase transformation from austenite grains with an average size of 3.4 μm, which are achieved by the deformation-induced reversal austenization during the high strain rate warm deformation. The main driving force for the reversal transformation is the stress. And the interval between the passes also plays an important role in the reversal austenization.

“…However, there are some residual cementite lamellas in the pearlite colonies. This may be attributed to the initial orientation of cementite lamellas [20,21].…”

Section: Effect Of Temperature Scheme On Microstructurementioning

confidence: 99%

Effect of Temperature Scheme on Microstructure and Mechanical Properties during Medium Carbon Steel Warm Processing

Fan

2019

Metals

Influence of temperature scheme on the microstructure and properties variation of medium carbon steel warm deformation was studied with testing equipment of Gleeble-3500, SEM, TEM, EBSD, and φ350 reversal rolling mill. The results show that the temperature of 650 facilitates the formation of ultrafine homogeneous microstructure. The microstructure formed during temperature range of 650–700 °C is relative homogeneous and fine. The mechanical properties of warm rolling are influenced by the cooling modes. The lower cooling rate is benefit to the combination of strength and ductility.