scholarly journals Influence of Strain and Stress Triaxiality on the Fracture Behavior of GB 35CrMo Steel during Hot Tensile Testing

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Zheng Li ◽  
Yajun Zhou ◽  
Sanxing Wang
Keyword(s):  
High Temperature ◽  
Tensile Testing ◽  
Crack Formation ◽  
Fracture Strain ◽  
Stress Triaxiality ◽  
Fracture Morphology ◽  
Tensile Tests ◽  
35Crmo Steel ◽  
Size Growth ◽  
High Temperature Tensile

To better understand cavitation nucleation and crack initiation in 35CrMo steel during high-temperature tensile processing and the effect of stress triaxiality on its fracture behaviors, uniaxial and notch high-temperature tensile tests were performed. The microstructure, fracture morphology, fracture strain, and stress triaxiality of the tested 35CrMo steel were then characterized and discussed. The results showed that crack formation in 35CrMo steel included stages of nucleation, growth, and microcavity aggregation. Scanning electron microscopy and energy-dispersive X-ray spectroscopy demonstrated that crack formation was closely related to the presence of steel inclusions. High-temperature tensile testing of samples with different notch radii showed that the fracture strain of 35CrMo steel was decreased with increasing stress triaxiality, that is, increased stress levels corresponded to decreased material plasticity. In addition, the recrystallization degree was decreased with increased stress triaxiality, and the grain size growth was slowed. The failure of 35CrMo steel occurred via ductile fracture, and low stress triaxiality, and high temperature conditions induced large and deep dimples on the fracture surface.

Further experiments and modeling for microscale compression molding of metals at elevated temperatures

2007 ◽  
Vol 22 (7) ◽  
pp. 1839-1848 ◽  
Author(s):  
J. Jiang ◽  
W.J. Meng ◽  
G.B. Sinclair ◽  
E. Lara-Curzio
Keyword(s):  
High Temperature ◽  
Aspect Ratio ◽  
Tensile Testing ◽  
Elevated Temperatures ◽  
Low Cost ◽  
Mold Insert ◽  
Compression Molding ◽  
Mechanics Model ◽  
Replication Technique ◽  
High Temperature Tensile

Replication of metallic high-aspect-ratio microscale structures (HARMS) by compression molding has been demonstrated recently. Molding replication of metallic HARMS can potentially lead to low-cost fabrication of a wide variety of metal-based microdevices. Understanding the mechanics of metal micromolding is critical for assessing the capabilities and limitations of this replication technique. This paper presents results of instrumented micromolding of Al. Measured molding response was rationalized with companion high-temperature tensile testing of Al using a simple mechanics model of the micromolding process. The present results suggest that resisting pressure on the mold insert during micromolding is governed primarily by the yield stress of the molded metal at the molding temperature and a frictional traction on the sides of the insert. The influence of strain rate is also considered.

Influence of SDAS on the High Temperature Tensile Behaviour of the C355 Al Alloy

2014 ◽  
Vol 783-786 ◽  
pp. 228-233 ◽  
Author(s):  
Lorella Ceschini ◽  
A. Jarfors ◽  
A. Morri ◽  
A. Morri ◽  
F. Rotundo ◽  
...  
Keyword(s):  
High Temperature ◽  
Hot Isostatic Pressing ◽  
Microstructural Characterization ◽  
Tensile Tests ◽  
Tensile Behaviour ◽  
Al Alloy ◽  
Casting Condition ◽  
Secondary Dendrite Arm Spacing ◽  
Heat Treated ◽  
High Temperature Tensile

The aim of the present study was to characterize the high temperature tensile behaviour of the C355 (Al-Si-Cu-Mg) alloy produced under controlled casting condition so as to obtain different secondary dendrite arm spacing (SDAS). C355 samples were produced through a gradient solidification equipment able to produce microstructures with fine (20-25 μm) and coarse (50-70 μm) SDAS values. The as-produced specimens were subjected to hot-isostatic pressing and then T6 heat treated. Microstructural characterization, room and high temperature (200 °C) tensile tests were carried out on the heat treated specimens. The tensile behaviour was related to the different SDAS value of the samples.

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