Microstructure Evolution Modeling and Simulation for Dynamic Recrystallization of Cr12MoV Die Steel During Hot Compression Based on Real Metallographic Image

Cen

et al. 2023

steel research int.

The flow stress curves of Fe‐31.7Mn‐11.5Al‐0.9C low‐density steel are obtained by a hot‐compression test with a Gleeble‐3500 thermomechanical simulator. It is shown in the results that the dynamic recovery and dynamic recrystallization (DRX) of δ‐ferrite occur preferentially under the same deformation condition, inducing a “yield point‐like” phenomenon in the true stress–strain curves. The Zener–Hollomon parameter is introduced to fit the characteristic parameters used to establish the flow stress model according to Arrhenius hyperbolic sine relationship and Avrami equation, and the DRX activation energy of austenite is 414.12 KJ mol−1. The hot‐processing maps at different true strains are simulated based on the dynamic material model to determine the suitable hot‐rolling process and the optimal hot‐working process selection of high strain rate and high deformation temperature combination, 1100–950 °C/1–0.2 s−1, is recommended.

“…The critical strain (

ε_{normalc}

) and saturation stress (

σ_{normals}

) can be obtained by work‐hardening rate‐true stress curve. [ 31 ]…”

Section: Resultsmentioning

confidence: 99%

Section: Drx Activation Energymentioning

confidence: 99%

See 1 more Smart Citation

Thermomechanical Treatment Performance and Flow Stress Model of a Fe–Mn–Al–C Low‐Density Steel

Cen

et al. 2023

steel research int.

“…In addition, it also has the advantages of small heat treatment deformation and strong loadbearing capacity. [13][14][15] It is widely used in various large and medium-sized cold working molds with large cross sections, complex shapes, and bearing large impact. [16,17] Generally, the Cr12MoV die is still manufactured by the traditional forging method.…”

Section: Introductionmentioning

confidence: 99%

Study on Microstructure and Mechanical Properties of Cr12mov Alloy Deposited by Laser Melting Deposition

et al. 2022

The deposition samples of Cr12MoV with different scanning speeds are prepared by laser melting deposition technology. Compared with forged Cr12MoV, the mechanism of laser melting deposition technology to improve hardness and wear resistance is studied. The tensile specimens of as‐deposited Cr12MoV are prepared by using the optimal process parameters. The fracture mechanism of as‐deposited Cr12MoV and the effect of deposition direction on its mechanical properties are studied. The phase composition and microstructure of deposited and forged samples are studied by X‐Ray diffractometry (XRD) and scanning electron microscope (SEM). The results show that the martensite in the as‐deposited Cr12MoV sample increases and has a finer grain size, which achieves the effect of fine‐grain strengthening. The hardness and wear resistance of the deposited Cr12MoV samples at three laser scanning speeds (4, 8, and 12 mm s−1) are better than those of the forged samples. The tensile fracture mode of the deposited Cr12MoV sample is an intergranular brittle fracture, and the sample perpendicular to the laser scanning speed has higher tensile strength and more excellent elongation.

Proceedings of the Institution of Mechanical Engineers, Part L:

“…These characterizations will make the mold prone to cracks and premature failure of the workpiece, which seriously affect the production efficiency and increase repair costs during service. [1][2][3] Therefore, how to effectively improve its performance and service life, and reduce the repair cost has become an urgent problem for researchers.…”

Section: Introductionmentioning

confidence: 99%

Microstructure and micro-hardness of Ni-based surfacing coating on the Cr12MoV die steel

Wei

Wang

2020

Ni-based surfacing coating was fabricated on the Cr12MoV die steel utilizing the ENiCrFe-2 alloy. The defect-free surfacing coating was obtained with a good metallurgical bonding between the coating and the substrate. The microstructure, element distribution, and micro-hardness were analyzed. Results showed that the microstructure was composed of planar crystals at the bottom of coating, and it consisted of columnar crystals at the middle region. There existed a diffusion layer with a width of about 100 μm at the ENiCrFe-2–Cr12MoV interface. Three regions were formed in the heat-affected zone with various microstructure morphologies. The average micro-hardness of coating was 275 HV0.5, which was more than that of Cr12MoV. Micro-hardness was dramatically increased (765 HV0.5) in the middle of the heat-affected zone. This was caused by the combined effect of grain refinement, solid solution strengthening, second-phase strengthening, and primary carbide strengthening. Moreover, the formation mechanism of middle heat-affected zone was discussed in this paper in detail.